xubuntu 12.04 boot problems

Use UUIDs in the fstab file instead of /dev/whatever. Those never change.

How does one find UUIDs for each device? Why does grub use /dev/xxxx? And why do all the the other entries in the GRUB menu boot and configure correctly? A little consistancy here would be good!!
I consider your answer a work-around not a solution.

sudo blkid

shows the UUIDs. It is not a work around at all. You will also notice the installation media has used the UUID as this never changes. Why and how is this a workaround in ANY way. You are using a naming scheme which is KNOWN to change and cause issues so UUIDs were then used to combat this. You are using the old problematic method. How is this a workaround?

think about it.....

It is a work-around because there is the issue of consistency. ie mount, fdisk, grub, install all use /dev/xxxx
I have setup /etc/fstab to use UUIDs and still have the boot hang with the first item in the grub menu.
UUID=99816d68-d512-4b53-8129-864618f3e241 in /etc/fstab. Which shows in fstab as being /dev/sda4 during install
(see the original post)

If it is a work around, why is it the norm in an Ubuntu install for at least the last four releases?

Did you look at the original post (the fstab listing)? It shows the install for / being on /dev/sda4 when 12.04 was installed.
I find the inconsistency very confusing and UUIDs very cumbersome.
Under 9.10 fstab has/had UUIDs in fstab for / , and this problem never did show up. It has the same two disks with the root partition
on the same phy device. The 9.10 partition is one of the menu items in the current Grub and does NOT have a problem.

UUIDs are great and will fix your issue. I have no other advise.

I DO appreciate your responses, they have moved me to look onto UUIDs. Also they may have helped/solved with
some of my problems and I am still getting familiar with UUIDs. It appears they are case sensitive, although I have
not found this documented.
Thanks for your responses!
I still see hangs in the boot process (of varing times)

some files or missing error xubuntu is not working after the current went the os its not booting

Update your grub. It seems there was a bug introduced in previous version which generated a grub.cfg with /dev/* instead of UUID.

The system in question has two hard drives with 4 linux partitions. There was one partition (ext3) that was not in /etc/fstab.
when I added an entry, using the UUID for this partition, the system no longer hung during the boot process.
Can anyone explain this? Has anyone else seen this?

P.S. There also are some fat & ntfs partitions on the hard drives, of which one fat partition is in /etc/fstab.