It's the same problem. Game starts up and I can start playing the first level. Frame rate it ok sometimes, really choppy sometimes.
After two or three minutes the screen goes black, but I can still move and fight (I can tell from the sounds). When I press esc to bring the menu up all there is no writing on any of the buttons, so I have to ctrl alt del to escape.
Thanks for the idea. Someone else suggested it might be my direct x. I've got verion 9.0c. Would this have anything to do with it?