Comment 2 for bug 822486

(Copied from http://ubuntuforums.org/showthread.php?p=11139820#post11139820)

Here's how I solved this problem:

Boot the 11.04 Live CD.

Switch to a terminal with Ctrl-Alt-F1.

Follow these instructions to mount your HD and get all the necessary /dev entries in a chroot enviornment:

http://www.cyberciti.biz/faq/ubuntu-...e-from-livecd/

Next, edit /etc/default/grub and comment out the line GRUB_HIDDEN_TIMEOUT=0

Run update-grub

Reboot. Now the SHIFT key *will* bring up the grub menu; hold SHIFT after your BIOS POST.

Select an older kernel. For me, 2.6.38-8 worked.

Your keyboard should now work. Go and do an update with the update manager to get the latest kernel.

Edit /etc/default/grub and put the line GRUB_HIDDEN_TIMEOUT=0 back in. Run update-grub. Reboot.

Worked for me. Your mileage may vary.