Comment 5 for bug 106260

I had also the problem: "waiting for root file system...". The problem arised due to kernel upgrade. Ubuntu changed partition names from hda to hdc, so i modificated /boot/grub/menu.lst line:

kernel /boot/vmlinuz-2.6.15-26-386 root=/dev/hda7
to:
kernel /boot/vmlinuz-2.6.15-26-386 root=/dev/hdc7

and i also modificated /etc/fstab on points where hda appears i changed it to hdc.
If you have mounted partitons, leave only names of the directory in /etc/fstab like they was:
example:
/dev/hdc5 /media/hda5 vfat defaults,utf8,umask=007,gid=46 0 1

Also, i do not know what changed, but my Ubuntu partition was on hda3, and now is on hdc7.
You can verify on which partition Ubuntu is by running gparted on Ubuntu Live CD.

That's all.