I remember having the same problem some time ago...
I used vista 64 at that time, and after checking really all known fixes the freeze appeared on and on.
Sometimes right after the map begun, sometimes i was able to play for about an hour,
but then suddenly it completely froze my pc, only a hard reset helped out.
I moved back to XP and it worked...so for me it was the OS that caused the problem.
Now im at win7 64, no problems here,too.