update manager says: installation from untrusted sources

Can you please give the output of:

uname -a; lsb_release -a; echo; sudo apt-get update

thanks

Here is the output:
---------------------------

hemant@hemant-HP-Mini:~$ uname -a; lsb_release -a; echo; sudo apt-get update
Linux hemant-HP-Mini 2.6.35-27-generic #47-Ubuntu SMP Fri Feb 11 21:01:29 UTC 2011 i686 GNU/Linux
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 10.10
Release: 10.10
Codename: maverick

[sudo] password for hemant:
Get:1 http://extras.ubuntu.com maverick Release.gpg [72B]
Ign http://extras.ubuntu.com/ubuntu/ maverick/main Translation-en
Hit http://archive.canonical.com maverick Release.gpg
Ign http://archive.canonical.com/ubuntu/ maverick/partner Translation-en
Hit http://security.ubuntu.com maverick-security Release.gpg
Ign http://security.ubuntu.com/ubuntu/ maverick-security/main Translation-en
Ign http://security.ubuntu.com/ubuntu/ maverick-security/main Translation-en_IN
Ign http://extras.ubuntu.com/ubuntu/ maverick/main Translation-en_IN
Hit http://extras.ubuntu.com maverick Release
Ign http://archive.canonical.com/ubuntu/ maverick/partner Translation-en_IN
Hit http://archive.canonical.com maverick Release.gpg
Ign http://archive.canonical.com/ maverick/partner Translation-en
Ign http://archive.canonical.com/ maverick/partner Translation-en_IN
Hit http://archive.canonical.com maverick Release
Ign http://security.ubuntu.com/ubuntu/ maverick-security/multiverse Translation-en
Ign http://security.ubuntu.com/ubuntu/ maverick-security/multiverse Translation-en_IN
Ign http://security.ubuntu.com/ubuntu/ maverick-security/restricted Translation-en
Ign http://security.ubuntu.com/ubuntu/ maverick-security/restricted Translation-en_IN
Ign http://security.ubuntu.com/ubuntu/ maverick-security/universe Translation-en
Ign http://security.ubuntu.com/ubuntu/ maverick-security/universe Translation-en_IN
Hit http://security.ubuntu.com maverick-security Release
Hit http://archive.canonical.com maverick Release
Hit http://extras.ubuntu.com maverick/main Sources
Hit http://security.ubuntu.com maverick-security/main Sources
Hit http://archive.canonical.com maverick/partner Sources
Hit http://archive.canonical.com maverick/partner i386 Packages
Hit http://extras.ubuntu.com maverick/main i386 Packages
Hit http://security.ubuntu.com maverick-security/restricted Sources
Hit http://security.ubuntu.com maverick-security/universe Sources
Hit http://security.ubuntu.com maverick-security/multiverse Sources
Hit http://security.ubuntu.com maverick-security/main i386 Packages
Hit http://security.ubuntu.com maverick-security/restricted i386 Packages
Hit http://security.ubuntu.com maverick-security/universe i386 Packages
Hit http://security.ubuntu.com maverick-security/multiverse i386 Packages
Hit http://archive.canonical.com maverick/partner i386 Packages
Hit http://packages.medibuntu.org maverick Release.gpg
Ign http://packages.medibuntu.org/ maverick/free Translation-en
Ign http://packages.medibuntu.org/ maverick/free Translation-en_IN
Ign http://packages.medibuntu.org/ maverick/non-free Translation-en
Ign http://packages.medibuntu.org/ maverick/non-free Translation-en_IN
Hit http://packages.medibuntu.org maverick Release
Hit http://packages.medibuntu.org maverick/free Sources
Hit http://packages.medibuntu.org maverick/non-free Sources
Hit http://packages.medibuntu.org maverick/free i386 Packages
Get:2 http://in.archive.ubuntu.com maverick Release.gpg [198B]
Hit http://packages.medibuntu.org maverick/non-free i386 Packages
Ign http://in.archive.ubuntu.com/ubuntu/ maverick/main Translation-en
Ign http://in.archive.ubuntu.com/ubuntu/ maverick/main Translation-en_IN
Ign http://in.archive.ubuntu.com/ubuntu/ maverick/multiverse Translation-en
Ign http://in.archive.ubuntu.com/ubuntu/ maverick/multiverse Translation-en_IN
Ign http://in.archive.ubuntu.com/ubuntu/ maverick/restricted Translation-en
Ign http://in.archive.ubuntu.com/ubuntu/ maverick/restricted Translation-en_IN
Ign http://in.archive.ubuntu.com/ubuntu/ maverick/universe Translation-en
Ign http://in.archive.ubuntu.com/ubuntu/ maverick/universe Translation-en_IN
Get:3 http://in.archive.ubuntu.com maverick-updates Release.gpg [198B]
Ign http://in.archive.ubuntu.com/ubuntu/ maverick-updates/main Translation-en
Ign http://in.archive.ubuntu.com/ubuntu/ maverick-updates/main Translation-en_IN
Ign http://in.archive.ubuntu.com/ubuntu/ maverick-updates/multiverse Translation-en
Ign http://in.archive.ubuntu.com/ubuntu/ maverick-updates/multiverse Translation-en_IN
Ign http://in.archive.ubuntu.com/ubuntu/ maverick-updates/restricted Translation-en
Ign http://in.archive.ubuntu.com/ubuntu/ maverick-updates/restricted Translation-en_IN
Ign http://in.archive.ubuntu.com/ubuntu/ maverick-updates/universe Translation-en
Ign http://in.archive.ubuntu.com/ubuntu/ maverick-updates/universe Translation-en_IN
Get:4 http://in.archive.ubuntu.com maverick-proposed Release.gpg [198B]
Ign http://in.archive.ubuntu.com/ubuntu/ maverick-proposed/main Translation-en
Ign http://in.archive.ubuntu.com/ubuntu/ maverick-proposed/main Translation-en_IN
Ign http://in.archive.ubuntu.com/ubuntu/ maverick-proposed/multiverse Translation-en
Ign http://in.archive.ubuntu.com/ubuntu/ maverick-proposed/multiverse Translation-en_IN
Ign http://in.archive.ubuntu.com/ubuntu/ maverick-proposed/restricted Translation-en
Ign http://in.archive.ubuntu.com/ubuntu/ maverick-proposed/restricted Translation-en_IN
Ign http://in.archive.ubuntu.com/ubuntu/ maverick-proposed/universe Translation-en
Ign http://in.archive.ubuntu.com/ubuntu/ maverick-proposed/universe Translation-en_IN
Hit http://in.archive.ubuntu.com maverick Release
Get:5 http://in.archive.ubuntu.com maverick-updates Release [31.4kB]
Get:6 http://in.archive.ubuntu.com maverick-proposed Release [31.4kB]
Hit http://in.archive.ubuntu.com maverick/main Sources
Hit http://in.archive.ubuntu.com maverick/restricted Sources
Hit http://in.archive.ubuntu.com maverick/universe Sources
Hit http://in.archive.ubuntu.com maverick/multiverse Sources
Hit http://in.archive.ubuntu.com maverick/main i386 Packages
Hit http://in.archive.ubuntu.com maverick/restricted i386 Packages
Hit http://in.archive.ubuntu.com maverick/universe i386 Packages
Hit http://in.archive.ubuntu.com maverick/multiverse i386 Packages
Get:7 http://in.archive.ubuntu.com maverick-updates/main Sources [89.7kB]
Get:8 http://in.archive.ubuntu.com maverick-updates/restricted Sources [778B]
Get:9 http://in.archive.ubuntu.com maverick-updates/universe Sources [35.8kB]
Get:10 http://in.archive.ubuntu.com maverick-updates/multiverse Sources [1,498B]
Get:11 http://in.archive.ubuntu.com maverick-updates/main i386 Packages [242kB]
Get:12 http://in.archive.ubuntu.com maverick-updates/restricted i386 Packages [1,797B]
Get:13 http://in.archive.ubuntu.com maverick-updates/universe i386 Packages [108kB]
Get:14 http://in.archive.ubuntu.com maverick-updates/multiverse i386 Packages [2,834B]
Get:15 http://in.archive.ubuntu.com maverick-proposed/restricted i386 Packages [14B]
Get:16 http://in.archive.ubuntu.com maverick-proposed/main i386 Packages [45.5kB]
Get:17 http://in.archive.ubuntu.com maverick-proposed/multiverse i386 Packages [1,124B]
Get:18 http://in.archive.ubuntu.com maverick-proposed/universe i386 Packages [16.1kB]
Fetched 609kB in 5min 37s (1,806B/s)
Reading package lists... Done
hemant@hemant-HP-Mini:~$

I just tried running the update manager. The 'untrusted software source' did not come up. I am in fact now downloading the updates. I do not why it worked now. I just ran those commands to provide output asked.

Thanks for your help.

Sometimes servers aren't updated synced, in this case just switch to main server.
https://help.ubuntu.com/community/Repositories/Ubuntu#Download%20Server

btw. you have proposed repo enabled which is for testing.
https://help.ubuntu.com/community/Repositories/Ubuntu#Ubuntu%20Updates

Ok and what is the output of:

sudo apt-get -y upgrade; sudo apt-get --reinstall install nano

Thanks

Here is the output of

sudo apt-get -y upgrade; sudo apt-get --reinstall install nano

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

hemant@hemant-HP-Mini:~$ sudo apt-get -y upgrade; sudo apt-get --reinstall install nano
[sudo] password for hemant:
Reading package lists... Done
Building dependency tree
Reading state information... Done
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
Reading package lists... Done
Building dependency tree
Reading state information... Done
0 upgraded, 0 newly installed, 1 reinstalled, 0 to remove and 0 not upgraded.
Need to get 208kB of archives.
After this operation, 0B of additional disk space will be used.
Get:1 http://in.archive.ubuntu.com/ubuntu/ maverick/main nano i386 2.2.4-1 [208kB]
Fetched 208kB in 5s (40.8kB/s)
(Reading database ... 280039 files and directories currently installed.)
Preparing to replace nano 2.2.4-1 (using .../archives/nano_2.2.4-1_i386.deb) ...
Unpacking replacement nano ...
Processing triggers for install-info ...
Processing triggers for man-db ...
Processing triggers for doc-base ...
Processing 2 changed doc-base file(s)...
Registering documents with scrollkeeper...
Setting up nano (2.2.4-1) ...
hemant@hemant-HP-Mini:~$

Ok all seems well, when do you get the untrusted output? Usually you get this sort of output:

W: GPG error: http://medibuntu.sos-sts.com edgy Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 2EBC26B60C5A2783
W: You may want to run apt-get update to correct these problems

Something like that, do you still see the error?

I do not get the error after I executed your first set of commands.

I used get a dialog box in update manager saying something to effect that the software is from untrusted source and there used to be a -sign in red ( i think this means 'prohibited' ) and there would be only one button 'close' in the box. On clicking close the update manager would simply revert to original state of displaying security and suggested update packages.
I can not reproduce this now, therefore the words may not be exact.

Is the situation still the same now?

I do not have the chance to check this now since I have now updated packages as I mentioned in one of my previous update.

Thanks for your help.