Silahsor

UPDATE: One of the oldest tricks in the book worked for me. What I did from Steam is Right Click on Game Library -> Properties -> Local Files -> Verify Integrity of Game Cache. I got the message that 2 viles cannot be verified and re-acquired. After that everything runs smoothly. Probably some of the game files were corrupted and repaired.

I also have the exact problem on Win-7 64-bit, Gtx 570 with latest driver. I get a large white boxes between fine pieces of map. Imagine a chess board: white squares with no background and black squares perfectly fine.