Hey.. Im sort of having the same problem, just not as intense. When I'm running 2 WoW's on this PC and have both windows open at the same time, it will become very glitchy.. textures will glitch out, etc. If I have it on too long then my computer will straight up freeze. Not really sure whats goin on but I'll try whiping out my old driver's and then reinstall them.
Comp specs: Intel Quadcore; 2Gigs DDR3; ATI 3870HD;
Edit: Looks like im still having the same problem after reinstalling the drivers Any ideas?
Also, after using maximizer my FPS has been capped at 100. How do I uncap it?
Thanks