Ubuntu
firefox package

Firefox not working

Asked by Rups

After installing ubuntu 10.10 i tried to install firefox-3.6.13 using the instructions given at this page
https://help.ubuntu.com/community/FirefoxNewVersion/MozillaBuilds but forgot to create backup of my default profile.
Did something wrong and firefox stopped working.If i click at the firefox icon....it shows "starting firefox" for sometime and then disappears.

So i uninstalled default firefox version and related plugins from ubuntu software center center.Then i installed firefox-3.6.13 using the following commands :

sudo apt-get update
sudo apt-get install firefox

Still the same problem.
Somebody plz help me fix this.....
Any kinda help is appreciated

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Eliah Kagan
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Eliah Kagan (degeneracypressure) said : 		#1

Follow steps 1 and 2 (but not 3, since you can't) under "Restore your old profile" at https://help.ubuntu.com/community/FirefoxNewVersion/MozillaBuilds. That will reset (i.e. empty out) your profile, and likely solve the problem. It will be as though you (i.e. your user account) had never run Firefox before.

I'm curious: Were you having some problem with Firefox as provided by Ubuntu? Why did you use the Mozilla build? 3.6.13 is the same version as provided in Maverick.

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Rups (rupsd) said : 		#2

Ubuntu 10.10 has firefox-3.6.10 ,not 3.6.13.
BTW:Tried that already but didn't worked.Need some other workaround.

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Theodotos Andreou (theodotos) said : 		#3

That's starnge! I have 3.6.13 and I use the official one! Can you use "Update Manager" to update your system?

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Rups (rupsd) said : 		#4

Still not running.Any other solutions??

Revision history for this message
Eliah Kagan (degeneracypressure) said : 		#5

You seem to be experiencing two problems here. One is that Firefox won't start. The other is that your system version of Firefox is lower than it should be, for a fully updated Ubuntu Maverick 10.10 system. These problems might be related, and they might not be.

To help figure out why Firefox is not starting, do the following:

(1) Run Firefox from a Terminal window (Applications > Accessories > Terminal, type in the command "firefox" without the quotes and press Enter), and paste the output (i.e. the additional text that appears in the terminal window after you press Enter) here. This may reveal messages that give information about the error that is occurring.

(2) Run the command "ls ~/.mozilla" (without the quotes) in a Terminal window and paste the output here. (This will tell us if steps 1 and 2 of "Remove your old profile" had the intended effect.)

(3) Create a new user account (System > Administration > Users and Groups and click Add). The new user doesn't need to have any administrative privileges. Log in as the new user, and try running Firefox. Does that work? (If it does, then that provides useful diagnostic information for arriving at an actual solution to this problem; we would then know that the problem is user-specific rather than systemwide. I do not expect you to log in with a different user account every time you run Firefox, though using a different user account might be a useful temporary workaround.)

(4) Were you having some problem with Firefox as provided by Ubuntu that motivated you to use the Mozilla build instead of the Ubuntu build? If so, then whatever that problem was could shed light on the problem you are currently having (so this question is not just a curiosity). Or did you install the Mozilla build because you thought it would provide you with a higher version of Firefox than Ubuntu's?

To help figure out why Firefox seems to be stuck at an earlier version, do the following:

(1) Describe the specific steps you take when you update your system.

(2) Run the command "apt-cache policy firefox" (without the quotes) in a Terminal window and paste the output here. (This will tell us for sure what version of Firefox is currently installed, and what version is currently available for installation.)

(3) Run "sudo apt-get update" followed by "sudo apt-get upgrade" in the Terminal, and paste the output of both commands here. (This will give us details of what the package manager is doing when it is updating your system, whether or not it is able to access all software sources, and if there are any packages that it is leaving at old versions.)

(4) Run "cat /etc/apt/sources.list" in the Terminal and paste the output here. (This will tell us which primary software sources you're using.)

(5) Run "ls -l ls -l /etc/apt/sources.list.d" in the Terminal and paste the output here. (This will tell us which, if any, PPA's you're using.)

(6) In your original post, you said: "Then i installed firefox-3.6.13 using the following commands" (followed by "apt-get update" and "apt-get install firefox"). Did you mean to say that you installed firefox-3.6.10, or did you **at one time** have the Ubuntu-provided Firefox 3.6.13 installed?

Revision history for this message
Rups (rupsd) said : 		#6

results:
1# No reaction

2#Related data

sudo ls -la ~/.mozilla gave

total 16
drwx------ 4 root root 4096 2011-01-11 04:49 .
drwxr-xr-x 43 rups rups 4096 2011-01-14 04:21 ..
drwx------ 3 root root 4096 2011-01-11 04:49 extensions
drwx------ 4 root root 4096 2011-01-11 04:49 firefox

sudo ls -la ~/.mozilla/firefox gave
total 20
drwx------ 4 root root 4096 2011-01-11 04:49 .
drwx------ 4 root root 4096 2011-01-11 04:49 ..
drwx------ 2 root root 4096 2011-01-11 04:48 Crash Reports
drwx------ 8 root root 4096 2011-01-11 04:56 ipaj6une.Default User
-rw-r--r-- 1 root root 114 2011-01-11 04:56 profiles.ini

Contents of profile.ini :

[General]
StartWithLastProfile=1

[Profile0]
Name=Default User
IsRelative=1
Path=ipaj6une.Default User
Default=1

sudo ls -la ~/.mozilla/firefox/"ipaj6une.Default User" gave

total 3908
drwx------ 8 root root 4096 2011-01-11 04:56 .
drwx------ 4 root root 4096 2011-01-11 04:49 ..
drwx------ 2 root root 4096 2011-01-11 04:49 bookmarkbackups
-rw-r--r-- 1 root root 16810 2011-01-11 04:49 bookmarks.html
drwxr-xr-x 2 root root 4096 2011-01-11 04:49 Cache
-rw------- 1 root root 65536 2011-01-11 04:56 cert8.db
drwxr-xr-x 2 root root 4096 2011-01-11 04:49 chrome
-rw------- 1 root root 165 2011-01-11 04:49 compatibility.ini
-rw-r--r-- 1 root root 150328 2011-01-11 04:49 compreg.dat
-rw-r--r-- 1 root root 7168 2011-01-11 04:49 content-prefs.sqlite
-rw-r--r-- 1 root root 2048 2011-01-11 04:49 cookies.sqlite
-rw-r--r-- 1 root root 2048 2011-01-11 04:53 downloads.sqlite
drwxr-xr-x 2 root root 4096 2011-01-11 04:49 extensions
-rw-r--r-- 1 root root 586 2011-01-11 04:49 extensions.cache
-rw-r--r-- 1 root root 552 2011-01-11 04:49 extensions.ini
-rw-r--r-- 1 root root 5191 2011-01-11 04:49 extensions.rdf
-rw-r--r-- 1 root root 4096 2011-01-11 04:49 formhistory.sqlite
-rw------- 1 root root 16384 2011-01-11 04:56 key3.db
-rw-r--r-- 1 root root 1456 2011-01-11 04:56 localstore.rdf
-rw-r--r-- 1 root root 3406 2011-01-11 04:49 mimeTypes.rdf
drwx------ 2 root root 4096 2011-01-11 04:49 minidumps
drwx------ 2 root root 4096 2011-01-11 04:53 OfflineCache
-rw-r--r-- 1 root root 0 2011-01-11 04:56 .parentlock
-rw-r--r-- 1 root root 2048 2011-01-11 04:49 permissions.sqlite
-rw-r--r-- 1 root root 143360 2011-01-11 04:49 places.sqlite
-rw-r--r-- 1 root root 0 2011-01-11 04:56 places.sqlite-journal
-rw------- 1 root root 2910 2011-01-11 04:53 pluginreg.dat
-rw-r--r-- 1 root root 1443 2011-01-11 04:56 prefs.js
-rw-r--r-- 1 root root 14565 2011-01-11 04:56 search.json
-rw-r--r-- 1 root root 2048 2011-01-11 04:49 search.sqlite
-rw------- 1 root root 16384 2011-01-11 04:49 secmod.db
-rw-r--r-- 1 root root 32768 2011-01-11 04:56 urlclassifier3.sqlite
-rw-r--r-- 1 root root 2250464 2011-01-11 04:53 XPC.mfasl
-rw-r--r-- 1 root root 100530 2011-01-11 04:49 xpti.dat
-rw-r--r-- 1 root root 1081803 2011-01-11 04:53 XUL.mfasl

sudo ls -la ~/.mozilla/firefox/"Crash Reports" gave

total 12
drwx------ 2 root root 4096 2011-01-11 04:48 .
drwx------ 4 root root 4096 2011-01-11 04:49 ..
-rw------- 1 root root 10 2011-01-11 04:48 InstallTime20100922073514

3# Yes its working in other account.

4#Actually found firefox-3.6.10 after a fresh install of ubuntu 10.10.
So i decided to manually upgrade to3.6.13.

---------------------------------------------------------------------------------------------------------------------------------------------------------

rups@rups-RD400-5-CD26A2:~$ apt-cache policy firefox
firefox:
  Installed: 3.6.13+build3+nobinonly-0ubuntu0.10.10.1
  Candidate: 3.6.13+build3+nobinonly-0ubuntu0.10.10.1
  Version table:
 *** 3.6.13+build3+nobinonly-0ubuntu0.10.10.1 0
        500 http://archive.ubuntu.com/ubuntu/ maverick-updates/main i386 Packages
        500 http://archive.ubuntu.com/ubuntu/ maverick-security/main i386 Packages
        100 /var/lib/dpkg/status
     3.6.10+build1+nobinonly-0ubuntu3 0
        500 http://archive.ubuntu.com/ubuntu/ maverick/main i386 Packages

rups@rups-RD400-5-CD26A2:~$ cat /etc/apt/sources.list
# deb cdrom:[Ubuntu 10.10 _Maverick Meerkat_ - Release i386 (20101007)]/ maverick main restricted
# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.

deb http://archive.ubuntu.com/ubuntu maverick main restricted
deb-src http://archive.ubuntu.com/ubuntu maverick main restricted

## Major bug fix updates produced after the final release of the
## distribution.
deb http://archive.ubuntu.com/ubuntu maverick-updates main restricted
deb-src http://archive.ubuntu.com/ubuntu maverick-updates main restricted

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team. Also, please note that software in universe WILL NOT receive any
## review or updates from the Ubuntu security team.
deb http://archive.ubuntu.com/ubuntu maverick universe
deb-src http://archive.ubuntu.com/ubuntu maverick universe
deb http://archive.ubuntu.com/ubuntu maverick-updates universe
deb-src http://archive.ubuntu.com/ubuntu maverick-updates universe

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team, and may not be under a free licence. Please satisfy yourself as to
## your rights to use the software. Also, please note that software in
## multiverse WILL NOT receive any review or updates from the Ubuntu
## security team.
deb http://archive.ubuntu.com/ubuntu maverick multiverse
deb-src http://archive.ubuntu.com/ubuntu maverick multiverse
deb http://archive.ubuntu.com/ubuntu maverick-updates multiverse
deb-src http://archive.ubuntu.com/ubuntu maverick-updates multiverse

## Uncomment the following two lines to add software from the 'backports'
## repository.
## N.B. software from this repository may not have been tested as
## extensively as that contained in the main release, although it includes
## newer versions of some applications which may provide useful features.
## Also, please note that software in backports WILL NOT receive any review
## or updates from the Ubuntu security team.
# deb http://in.archive.ubuntu.com/ubuntu/ maverick-backports main restricted universe multiverse
# deb-src http://in.archive.ubuntu.com/ubuntu/ maverick-backports main restricted universe multiverse

## Uncomment the following two lines to add software from Canonical's
## 'partner' repository.
## This software is not part of Ubuntu, but is offered by Canonical and the
## respective vendors as a service to Ubuntu users.
# deb http://archive.canonical.com/ubuntu maverick partner
# deb-src http://archive.canonical.com/ubuntu maverick partner

## This software is not part of Ubuntu, but is offered by third-party
## developers who want to ship their latest software.
deb http://extras.ubuntu.com/ubuntu maverick main
deb-src http://extras.ubuntu.com/ubuntu maverick main

deb http://archive.ubuntu.com/ubuntu maverick-security main restricted
deb-src http://archive.ubuntu.com/ubuntu maverick-security main restricted
deb http://archive.ubuntu.com/ubuntu maverick-security universe
deb-src http://archive.ubuntu.com/ubuntu maverick-security universe
deb http://archive.ubuntu.com/ubuntu maverick-security multiverse
deb-src http://archive.ubuntu.com/ubuntu maverick-security multiverse

rups@rups-RD400-5-CD26A2:~$ ls -l ls -l /etc/apt/sources.list.d
ls: cannot access ls: No such file or directory
/etc/apt/sources.list.d:
total 4
-rw-r--r-- 1 root root 92 2011-01-14 04:03 tualatrix-ppa-maverick.list

6#I found 3.6.10 preinstalled.
Tried manually to upgrade to 3.6.13

3# step skipped.it asks me to download 155 mb when i give sudo apt-get upgrade

Revision history for this message
Rups (rupsd) said : 		#7

This is the install log.

rups@rups-RD400-5-CD26A2:~$ sudo apt-get install firefox
[sudo] password for rups:
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following extra packages will be installed:
  firefox-branding
Suggested packages:
  firefox-gnome-support firefox-kde-support ttf-lyx
The following NEW packages will be installed:
  firefox firefox-branding
0 upgraded, 2 newly installed, 0 to remove and 207 not upgraded.
Need to get 11.6MB of archives.
After this operation, 31.0MB of additional disk space will be used.
Do you want to continue [Y/n]? y
Get:1 http://archive.ubuntu.com/ubuntu/ maverick-updates/main firefox-branding i386 3.6.13+build3+nobinonly-0ubuntu0.10.10.1 [211kB]
Get:2 http://archive.ubuntu.com/ubuntu/ maverick-updates/main firefox i386 3.6.13+build3+nobinonly-0ubuntu0.10.10.1 [11.4MB]
Fetched 11.6MB in 22min 4s (8,752B/s)
Selecting previously deselected package firefox-branding.
(Reading database ... 118022 files and directories currently installed.)
Unpacking firefox-branding (from .../firefox-branding_3.6.13+build3+nobinonly-0ubuntu0.10.10.1_i386.deb) ...
Selecting previously deselected package firefox.
Unpacking firefox (from .../firefox_3.6.13+build3+nobinonly-0ubuntu0.10.10.1_i386.deb) ...
dpkg: warning: unable to delete old directory '/usr/lib/firefox-3.6.10/components': Directory not empty
Processing triggers for desktop-file-utils ...
Processing triggers for python-gmenu ...
Rebuilding /usr/share/applications/desktop.en_US.utf8.cache...
Processing triggers for python-support ...
Setting up firefox-branding (3.6.13+build3+nobinonly-0ubuntu0.10.10.1) ...
Setting up firefox (3.6.13+build3+nobinonly-0ubuntu0.10.10.1) ...
Installing new version of config file /etc/apport/blacklist.d/firefox ...
Installing new version of config file /etc/apparmor.d/usr.bin.firefox ...
update-alternatives: using /usr/bin/firefox to provide /usr/bin/x-www-browser (x-www-browser) in auto mode.
Please restart all running instances of firefox, or you will experience problems.
rups@rups-RD400-5-CD26A2:~$ firefox -ProfileManager
rups@rups-RD400-5-CD26A2:~$ ~/firefox/firefox -ProfileManager
bash: /home/rups/firefox/firefox: No such file or directory
rups@rups-RD400-5-CD26A2:~$ sudo rmdir /usr/lib/firefox-3.6.10
rmdir: failed to remove `/usr/lib/firefox-3.6.10': Directory not empty
rups@rups-RD400-5-CD26A2:~$ sudo rmdir /usr/lib/firefox-3.6.10/components
rmdir: failed to remove `/usr/lib/firefox-3.6.10/components': Directory not empty
rups@rups-RD400-5-CD26A2:~$ sudo ls /usr/lib/firefox-3.6.10/components
compreg.dat xpti.dat

I removed that dir manually

Revision history for this message
Sam_ (and-sam) said : 		#8

## sudo ls -la ~/.mozilla/firefox/"ipaj6une.Default User ##

You don't need 'sudo' to list apps in your /home directory.
Actually there shouldn't be anything in /home/user which needs root permissions.
As you can see from output root is the owner of all files in ~/.mozilla.
You need to grant permission to user in order to run Firefox as user.
You should not run Firefox as root.

https://help.ubuntu.com/community/FilePermissions

Revision history for this message
Best Eliah Kagan (degeneracypressure) said : 		#9

The existence of ~/.mozilla indicates that steps 1 and 2 of "Restore your old profile" (https://help.ubuntu.com/community/FirefoxNewVersion/MozillaBuilds) were not performed successfully. (You may recall that I said that even though you could not restore the old profile, since you are unable to perform step 3, you can still remove the current one by performing steps 1 and 2.) The .mozilla folder inside your home folder contains all your user-specific Firefox profile information. Considering that Firefox works when you run it as another user, removing ~/.mozilla should solve your problem getting the Ubuntu-provided Firefox to work. The absence of a profile for your user will cause Firefox to automatically create one with a default configuration that works.

To accomplish this, run:

mv ~/.mozilla ~/.mozilla-broken

If that fails (i.e. produces an error message), then run it with sudo. If that fails as well, then please post again with the error message (or both error messages, if the error message when you run it without sudo is different from the error message when you run it with sudo).

That command doesn't actually erase your profile--it just renames it so it won't be recognized by Firefox, and thus won't get in the way. If you want to completely erase the information even though it is not necessary to do so, then (assuming you have renamed the folder from .mozilla to .mozilla-broken) you can run "rm -rf ~/.mozilla-broken". That command won't display an error message even if it fails, so to see if it succeeded, run "ls -d .mozilla-broken". If the output of that second command is "ls: cannot access .mozilla-broken: No such file or directory" then the .mozilla-broken folder is successfully removed. Note again that this step is entirely optional.

Any operating system (Ubuntu or otherwise) will contain old versions of its components when it is first installed. That is why it is important to update the system after installation. If you had updated your system (e.g., with System > Administration > Update Manager, or by running "sudo apt-get update" followed by "sudo apt-get upgrade"), Firefox 3.6.10 would have been automatically upgraded to Firefox 3.6.13 (like it is now).

If you want to run Mozilla builds of Firefox, you can certainly do so, and you can probably get that to work properly. Samantha (aka Sam)'s post should point you in the right direction, if you really want to run Firefox that way. But the vast majority of Ubuntu users (whether they be novices or experts) are best-served by running the Ubuntu build of Firefox (provided by the Ubuntu package), unless they want to run an unstable version. If you manually install a Mozilla build of Firefox inside your home folder, then you will have to manually keep it up to date; whereas if you use the Ubuntu version of Firefox, then updating the system will automatically install security and stability updates to Firefox, without any effort on your part.

Revision history for this message
Eliah Kagan (degeneracypressure) said : 		#10

To elaborate on one of Samantha (aka Sam)'s points:

You should avoid running Firefox as root, unless (1) you really know what you're doing (i.e. understand the implications for permissions on your configuration files, which involves having specific knowledge of Firefox internals), and (2) you have a specific reason why you need to run it as root.

If you think you need to run Firefox (or any graphical web browser) as root while logged on as a non-root user, you should first consider if there is another way to accomplish your goal. For example, if you need to download a file into a directory owned by root, you could download it as yourself and then move it to that directory as root (e.g. with sudo), or you could download it as root with a simpler application like wget or curl (which don't have configuration files that can be rendered inaccessible by an unprivileged user after being touched by root).

Revision history for this message
Rups (rupsd) said : 		#11

Thanks Eliah Kagan, that solved my question.

Revision history for this message
Rups (rupsd) said : 		#12

@sam
Once i downloaded firefox-3.6.13 and tried to run it from home directory but it showed "permision denied.cannot run child process".
So does it was because of owner permissions?
And how i will find whether firefox is running as root?

Revision history for this message
Sam_ (and-sam) said : 		#13

As suggested above verify that all directories and files belong to user.
If Firefox is running as root you did actively start it as such where it would request a password.
Processes can be viewed in terminal by:
top

Revision history for this message
Eliah Kagan (degeneracypressure) said : 		#14

When Firefox runs for the first time, it creates a profile. Specifically, it creates a folder called .mozilla inside your home folder, and then puts files in that folder that store user-specific information. If you run Firefox as yourself, then it is your user account that creates ~/.mozilla and its contents, so ~/.mozilla and its contents typically are owned by your user account. Then, viewing ~/.mozilla and its contents with the ls command (or right-clicking on it in Nautilus, clicking Properties, and going to the Permissions tab) would reveal that your user account is the owner.

But if you run Firefox for the first time as root, then it will be the root user account that creates ~/.mozilla and its contents, so those files will be owned by root instead of by your user account. That can prevent Firefox from being run by your user account. That was probably the cause of your problem, where you could not run even the Ubuntu-provided Firefox.

When you run a program without doing anything special to run it as root, it typically runs as your user. Programs like sudo, su, gksu, gksudo, and su-to-root will run your program with alternate user credentials--unless you specify a user, they will run it as root. As you probably know, every time you run a command with sudo, you are running it as root. You should avoid running commands with sudo unless you know that you really need to run them as root, because (1) some commands, like "firefox", can create files owned by root or cause root to take ownership of files, which would then break functionality when you're not running as root, (2) programs run as root don't always interact properly with programs running concurrently as the logged-in non-root user, (3) running a program as root gives it great power, enabling it to cause harm if you make a mistake while running it or the program is written in a way that is insecure or unstable, and (4) you might run a command containing a typo as root by accident and harm your system (and the less frequently you run commands as root, the less likely this will happen). Even professional UNIX system administrators, who perform numerous actions every day as root, will avoid running programs as root when it is not necessary to do so.

When you create a launcher in Nautilus to run a program, you can put "gksu" in front of the command to make it so that the program gets run as root. The gksu program will (on a properly configured Ubuntu system) ac t as a wrapper to sudo, but if it has to ask for the user's password, it will ask for it graphically (if it asked for it on the console, you'd never see the prompt, since output to the console is not displayed when you run a program by double-clicking on its launcher in Nautilus). If you don't put anything in front of the command, then unless you are running Nautilus itself as root, double-clicking the launcher will run the program as your user account and not as root. The same applies to Nautilus--if you're logged on with a regular user account, you would have to do something special to run Nautilus as root.

(There is one exception to this. One of the permission flags that can be set on a file in a Unix-style filesystem is the "setuid" bit. Normally, when the setuid bit is not set, a file owned by user A and run by user B runs as user B. That's almost always a very good thing. But when a file's setuid bit is set, and the file is owned by user A, and user B runs the file, the file runs as user A. This is important for some special programs in the system, but this behavior is rarely desirable and often has disastrous consequences, especially when the file is owned by root. Unless you know exactly what you're doing, don't make a file setuid. The setuid bit on a folder means something different, but you shouldn't set it unless you know what you're doing either. The Wikipedia article http://en.wikipedia.org/wiki/Setuid provides a good introduction to setuid/setgid. Please note that this paragraph is purely informative, and to ensure that the preceding paragraph's incompleteness does not render it incorrect. It is extremely unlikely that any of the problems you have been having with Firefox have anything to do with the setuid bit, and even more unlikely that you would ever want to set a setuid bit on any file that is part of Firefox or a Firefox user profile.)

As Sam says, you can view currently running processes in the Terminal with top, but that will not show you all of them, and it will not necessarily show you the process you're interested in. To find out if a program that is currently running is running as root, you can run the command:

ps aux | grep -v grep | grep program-name

This actually does something a bit more general--it spits out a list of all the running programs that were started by commands that contained program-name, along with information about the running programs including the user they're running as. (Change program-name to the name of the actual program, e.g. firefox.) When I say "started by commands," this doesn't mean only programs that you started by typing in commands--even programs started automatically or by other programs have a "command" associated with them. If the name you consider to be the program's name isn't actually part of the command-line that runs it, then this won't work. For example, "ps aux | grep -v grep | grep 'Update Manager'" won't tell you about running instances of the Update Manager; for that, you would need "ps aux | grep -v grep | grep update-manager". Similarly, when searching for Firefox, use "firefox" and not "Firefox". Note that "| grep -v grep" makes it exclude programs whose command line contain grep, which is usually what you want.

For example, on one of my systems, when I run the command "ps aux | grep -v grep | grep firefox" I get:

ek 2611 0.0 0.0 1896 508 ? S 16:58 0:00 /bin/sh /usr/lib/firefox-3.6.13/firefox
ek 2615 0.0 0.0 1896 504 ? S 16:58 0:00 /bin/sh /usr/lib/firefox-3.6.13/run-mozilla.sh /usr/lib/firefox-3.6.13/firefox-bin
ek 2619 15.6 4.9 241428 51224 ? Sl 16:58 0:02 /usr/lib/firefox-3.6.13/firefox-bin

These are the three processes actually associated with Firefox (as it runs on my system--yours may be different if you're using the Mozilla build). You can see that they're all running as "ek" (my username), which is desirable. If you saw "root" instead of "ek" (or instead of your username), that would tell you that Firefox was running as root.

The "permission denied. cannot run child process" error message in Nautilus probably indicates that there is something wrong with the file permissions on one or more of the files that you extracted into ~/firefox (or with the permissions on the ~/firefox folder itself). You can manually change the permissions to try to get it to work, but you really shouldn't. You might change the permissions to something that is initially functional, but which causes problems later. This would also be the case if you were an expert user, unless you knew exactly what the permissions on each file in the archive was *supposed* to be. Changing the *owner* of the ~/firefox folder is safer (e.g. if it's owned by root, you could change it from root to your username, so long as you changed it for the entire contents of the folder). But in my opinion, that's not the best solution either. Instead, you should delete the ~/firefox folder and re-extract the archive.

Since you sometimes run commands as root with "sudo" even when it is not necessary to do so, my guess (and this is just a guess) is that when the instructions at https://help.ubuntu.com/community/FirefoxNewVersion/MozillaBuilds told you to run "tar jxf firefox*.tar.bz2 -C $HOME", you ran "sudo tar jxf firefox*.tar.bz2 -C $HOME" instead. Make sure to run it *without* sudo. If you extract the archive as root, then root creates ~/firefox and all the files therein, so they get owned by root instead of by your own user account.