Vista 32 Freezes - Hardware Issue (I think)

I have been trying to diagnose an issue for a decent amount of time right now and can't come up with a thing.

Here is the basic problem and some of the things I have tried:

Warcraft 3 freezes.. This game is by no means a system hog. It's an intermittent error and is really causing my win % to slide

I know that it isn't software related. Vista's problem log is not updating when it crashes. There are no War3 errors.

It isn't my memory. Memtest runs fine.

My GPU runs hot, but not too hot. about 66C.

I think I have a shitty mobo, and that could be most of the problem... I would just like to no for sure. It's a NF650iSLIT-A (V1.0) running a core 2 duo 3 ghz. I also am only running with 2gb of memory.. I'm going to remedy that problem right now.

Any other thoughts?