Ubuntu version upgrade.
AND entries to boot new kernel written incorrectly to /boot/grub/menu.lst (because of long time previously described disk detection error) so restart after upgrade booted into old kernel.
After reboot the package manager assumed it was okay to continue the upgrade.
Suggestion to upgrade scripting people: sanity check kernel version before continuing with upgrade.
Adept seemed to be quite unstable and failed.
Ended up with a system which would boot but had no network, or graphics.
When I fixed graphics (X) we had no mouse or keyboard. AGH! B0rked.
Download .iso for ubuntu 9.1 jaunty.
Make various backups.