boot splash screen runs in unsuported mode by monitor

Ok so I never thought I would have a monitor problem but I have one now I have no idea how to fix. I switched monitors with my wife and now I have the flat panel LCD. However when I boot the initial boot screen is just fine but when it switches to the welcome to Knoppix screen with the list of services and hardware being started (henceforth called the splash screen) the image is blurry and is displayed split in half horzontaly. When the machine finishes booting all is fine. While its doing this funky split thing the monitor displays a msg "mode not supported. How do I, or can I change the monitor settings for this portion of the boot up. It does the same thing with kanotix and gentoo. I can't setup gentoo because the whole setup is in this funky mode and is unreadable. Can I force the startup to use the same v and h sync rates as the system has once fully booted? Any ideas?

Computer:
Iwill xp333 mb
amd athlon xp1800 cpu
512 mb ram
sis 315 agp video card

Monitor: Sylvania LCD

It also does this when the system is shutting down.