I have a laptop with the same issue. I found the answer on the Ubuntu forums - add nomodeset to the kernel line in lilo.conf. If you have another PC you can connect to it via ssh and edit lilo config, otherwise you may have to reboot, mount filesystems, run pkgtool and reconfigure the bootloader or edit it by hand and run lilo.
Code:
# Append any additional kernel parameters:
append=" vt.default_utf8=0 nomodeset"
Andy.