In Game Graphics Issue

Beginning last night I started experiencing issues with the game. I can view and move my character around just fine, but the background graphics are distorted or sometimes missing altogether. I have updated all bios and drivers for my pc to no avail. Nothing has happened to the pc that would account for this problem, so I think it may be program or game related. I have been playing on this laptop since December 2010 without issue.

I am running Windows 64 bit Intel i5 CPU M 460 @ 2.53 Ghz

1GB ATI Mobility Radeon HD 5650 graphic card

Any help or suggestions on how to resolve this would be GREATLY appreciated :)

Thank you