HELP I destroyed my wife's computer (while upgrading to Feisty -- UUID Grub issue)

[Chanchao]

Seems I cheered to early yesterday about how easy it is to upgrade to
Feisty... Indeed I upgraded the Mrs's laptop but thought everything was
well.  Serves me right.

When I start it up it boots into Grub normally, but then when starting
Ubuntu it complains about not being able to find/mount the root block
and then dies with a kernel panic.

I then downloaded the Feisty Live/Installer Cd initially fully intending
to just wack the lot and do a fresh install, but curiosity led me to
check the menu.lst in grub and find out it too caught a bad case of
using UUIDs.. I already had loads of trouble with those in fstab when
upgrading to Edgy.  (Why is this even necessary, using UUIDs when the
old method worked fine and the new one clearly doesn't work fine in all
cases yet)

So what do I do?  I tried to change from root=UUID=blabla to
root=/dev/hda2 (I assume it's HDA2 not SDA2, on the Live Cd is showed as
SDA but that could be just a live-CD-thing?  It's not a SCSI disk or
anything, just a plane old harddisk in a laptop. 

Still it didn't work.  I think I tried all likely options
like /dev/hda2, /dev/sda2, etc.  (Why doesn't the upgrade to Feisty
leave a backup of the original menu.lst file by the way..)

As a separate issue, Feisty is the first Ubuntu live CD that DID NOT
boot up properly on that same laptop. Failed to start GDM showing crap
about the Xserver and asking me if I want to see log info..   In the end
got it tow work by specifying VGA and 16 colors, even though it then DID
end up properly with full resolution and full colors.   Weird.

Was Feisty really ready for release?  It works as reliable as everything
before it after installation/upgrade, however it seems we made backward
progress on the installation/upgrade process itself.

Cheers,
Chanchao