Black and White 2 Freezing

[Unromantic__Me]

I recently built my own computer with gaming in mind, I had hoped that every game out at the moment would be able to be tamed by it. Black And White 2 seems to have crushed that hope! Whenever I load it up, at some point during the game it will freeze; it may be 10 seconds in or it may be an hour in but it will freeze, forcing me to reset the system. I would appreciate any help you all could offer me! Is it instablilty within the system? Have I not plugged something in that i should have? I really have no clues what so ever! Please note this also happens on the Dawn Of War demo and the psychonauts demo.
Rig:
xp professional 64 bit
2gig GeIL value PC3200
AMD Athlon 64 4200+
Asus A8N-SLi SE nForce4 SLi motherboard
2x Nvidia 6800 GS