I have had several lock ups during a game where the screen freezes and the sound loops over a small sound, ie stutters. I am sometimes able to alt-tab, but the game stays up with the window control bar appearing below. I am not sure what is the cause of this. I recently updated both my motherboard and graphics card drivers as well as directx 9 to the most recent version.

My system specs are as follows
amd athalon 2800
9600 AtI Radeon with 128 meg rams
nforce 2 motherboard
running custom mouse driver - Razer Diamondback