i just tried to update menu.lst manually and then did update-grub perhaps this error message is helpful. of course im certain of the UUID - i got it from /dev/disks/by-uuid and it seems to work in fstab every time
Searching for GRUB installation directory ... found: /boot/grub findfs: Unable to resolve 'UUID=18942279-eaf5-4e86-a174-8b04b5d3127e' Cannot determine root device. Assuming /dev/hda1 This error is probably caused by an invalid /etc/fstab Testing for an existing GRUB menu.lst file ... found: /boot/grub/menu.lst Searching for splash image ... none found, skipping ... Found kernel: /boot/vmlinuz-2.6.20-10-generic Found kernel: /boot/vmlinuz-2.6.20-9-generic Found kernel: /boot/memtest86+.bin Updating /boot/grub/menu.lst ... done -- GRUB's menu.lst modified in wrong way -> Error 15 File not found on next reboot https://launchpad.net/bugs/61108 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs