I have been having random crashes while playing, about once every 15 minutes or so depending on where I was. I tried disabling SLI on my two GTX 275s, and I haven't had a crash since (about 3 hours of play time). Unfortunately that comes at a slight framerate hit, but at least I can play now. Also, setting water reflections to medium solved my periodic stutter while outside.

Win 7 Home 64 bit
Intel i7 920@2.67
6 gig ram
NVIDIA GTX 275 SLI (err, not anymore)

bump in case this helps anyone else...