I investingated a bit and it seems that update-manager takes the kernel parameters from fstab (where I have the correct UUIDs) unless kopt options are present in grub configuration's file. And my menu.lst had these two lines:
# kopt=root=UUID=... # kopt_2_6=root=/dev/hda2 So the last line was used as the kernel root parameter. I deleted that line and update-grub worked as expected using UUID. Anyway something must be done to prevent this. -- [feisty] wrong menu.lst makes booting imposible https://launchpad.net/bugs/78901 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
