I run a 5970, I7 930, 6 gigs ram

My fps stays usualy 55-60 fps out side of town , in town 30-60 , in fullscreen crossfire, but i get a strange horizontal blurred line that shows up so i have to run it off one gpu of my 5970 in windowed mode, and when i run it that way i usualy run about 40-60 out side of town , and like 25-55 inside of town, but i dont have the crappy horzintal limne blur.
I've tried every driver , still same problems.

They need to do something about crossfire, my rig is currently running crysis 2 on max settings in fullscreen with no problems. Its the programming in this game thats the problem imo.