Sometimes this happens to me after playing long periods of time. Some colors go black and all colors start strobing... man it is frustrating.
This happens mostly at map changes when I have been playing for a long time. If I continue playing it often ends up crashing or w/ BSD *blue screen of death. Then I have to hard restart my system. Now when it starts I will just log out for a bit, or restart system totaly, and it fixes it.
Seems to be driver issues w/ graphics cards, or possible over heating of GPU. Recently blew the cobwebs out of my system and it helped cooling.
Windows 7 may help you with the dx10 capability.