My game crashes after 15-20mins of play time. Is there anything I can do attempt to hold off the crashes? Every hour wouldn't be so bad.

My specs are: AMD 3.6ghz 965 quad cpu, 16gb DDR3 1600 vengeance ram by corsair, ASUS crosshair IV m/b, HD 5870 ati card 1gb by XFX, 64bit windows 7, X-Fi sound blaster 7.1 sound, WD cavier black 7600rpmg 750gb hardrive, high speed cable internet. My machine is stable and bug free so...

I run the game ins 1600x900 because that's my monitors default setting.

Edit* I have every thing graphical in game set to the maximum and my video game is set to highest quality. If I set things down would that help at all?