You could put the necessary boot option ( xvrefresh=?? ) in your /etc/lilo.conf file append line ie:
...
append="hda=scsi hdb=scsi hdc=scsi hdd=scsi hde=scsi hdf=scsi hdg=scsi hdh=scsi apm=power-off nomce xvrefresh=72"
...
and then re-run lilo with /sbin/lilo -v

Or another way would be to boot to your CD and play with the boot options (cheat codes, press F2 at startup or read the cheatcodes.txt file on your cd). Once you have your video working like you want it mount your hard drive read-write rename your old XF86Config-4 file just in case and copy the new file into /etc/X11 on your hard drive.

HTH

rock