Hey!!!
Thats what my game does to(Ghost Recon Advanced Warfighter 2). I can play for a few minutes and then the screen goes black and a message will say

VERTEX BUFFER LOCK
PHYSICS - threaded
RENDERING - threaded

I am going to get FS ONE but jeese, i hope that doesnt happen to me again. If any one knows how to fix the problem we could use the help!

Good luck with your computer.