White bar flickering at bottom of screen

[Dr_Schnatz]

Hi,
I've been able to play for an hour before getting a series of game freezes where i have to shutoff computer cold turkey(windows key/ctrl*alt*delete* not working). I've now updated my graphics cards (2 Nvidia 8800 GT in SLI mode) cleaned my registry, and defragged computer. Now i have resumed playing and now i have approx 3 white bars flickering at the bottom of the screen(flickering doesnt occur in Game menus). Been playing for 15 minutes like this without freezing(hopefully updating did something) but it is starting to get annoying/ impeding quality of game. Ive spent more time dealing with problems than enjoying your product. Feedback Would be Wonderful.(included attached screenshot of issue)

System information(Exceeds minimum requirements so positive isnt hadware problem as i run alot of current games on high without graphical issues/freezes)
Processor: Intel(R) Core(TM)2 Quad CPU Q6600 @ 2.40GHz (4 CPUs), ~2.4GHz
Memory: 4094MB RAM
Card name: (2) NVIDIA GeForce 8800 GT
Display Memory: 2286 MB
Dedicated Memory: 495 MB
Shared Memory: 1791 MB
Current Mode: 1600 x 900 (32 bit) (60Hz)