[DogMeat]

First thing to do is make sure you can run other programs that do the same thing MoHAA does and see how they work. This means trying out Quake 3 Arena, Unreal Tournament, 3D Benchmark, etc. It may just be something specific to MoHAA or it might be effecting you systemwide, this will help find out.

You also may want to try clearing your BIOS with the 512 in there, and then only make minimal changes to it, leave everything else default.

Aside from that, video card drivers are always a good thing to check, for brands that include a "full uninstall" program or procedure use it and first try an earlier "stable" release of their drivers and gradually move up to trying the latest, including beta drivers if need be.

Good luck, hope some of this helps.