After upgrading my Debian Etch system and getting a new kernel, none of the entries in the GRUB menu worked. And the entries for Windows XP were gone.

Trying to boot into Debian gave me "Error 17: cannot mount selected partition".

In /boot/grub/menu.lst I changed everything that said hd0,1 into hd0,0 and all hda2 into hda1 and now Debian does work.

What has happened? From my backup menu.lst's I can see that hd0,1 and hda2 were the right choices before, and now that has changed. Isn't that weird?