2D problems with 965P and 7900GT, anyone experience this?

[Veraxitas]

I have a Asus P5B with 6600 conroe, 2gb Corsair XMS PC6400 and a Gforce 7900GT. I used the same video card on my DFI board (939) with no problems. Ever since I moved it to my P5B I am expereincing 2D lag, things seems to tile, or wipe off the screen instead of just popping off like they should. Someone told me it was an exeleration problem but didnt know how to fix it. I am using the latest nvidia drivers too. Also, I have also used this same setup on a Gigabyte DS3 and didnt experience this problem. Seems to be something with the P5B. Any thoughts??