5900 and 8900 prp problems

OK build this computer runs great but have a weird problem.
First installed a FX5900 games ran great then after 5 reboots playing unreal003 would load with very weird colors(like when u are on acid)

when playing quakeIII game would look great but the desktop was on acid.

MechcommanderII played without problems

Thought it was a vid card problem, returned it and got a 9800 pro.

Unreal looks great but when loading quake the desktop is doing the same thing. DO I have a bad mobo or drivers what is it, it is driving me crazy.

This card also has no problems with mechcommander.


Tx for your time.

Learux