Try to add this kernel option to the
line in your /etc/lilo.conf:
Don't forget to run lilo afterwards.
The error description you provide points to problems with kernel mode setting, it seems that the driver sometimes has problems to determine the correct resolution and/or refresh rate for your monitor. The option mentioned above will instruct the driver to use a resolution of 1024x768 with a refresh rate of 60Hz, a standard resolution any modern display should work with. Use the native resolution of your display instead of those settings, if you wish.