Help with "partition not found" after 12.04 upgrade

[Charlie Zender]

Am having the worst upgrade experience of the entire Ubuntu series.
Just tried oneiric->precise kubuntu, i.e., 11.10->12.04:
Things seemed to be going smoothly until the reboot at the end.
Now system stops at the grub bootloader stage: every kernel I
choose to boot (regular, safe-boot, my windows partition, or
older Ubuntu kernels) responds with multiple copies of the same
error message: "partition not found". Nothing boots.

Since I can't boot anything, how can I "fix" the system (grub's
menu.lst? /etc/fstab?) without having to do a fresh install?

Thanks!
Charlie
-- 
Charlie Zender, Department of Earth System Science
University of California, Irvine 949-891-2429  )'(