I'm having the same issue on my Dell Inspiron 9300 notebook. Brief specs:
-Pentium M 1.73Ghz
-256MB NVIDIA GeForce GO 6800 Forceware v78.11
-Audigy 2 ZS Notebook PCMCIA Card
I've tried the "/audiomixbuffer 50" switch with no luck. The game just hangs and I have to manually reset the notebook. This happened with the BETA version as well. I've closed all background apps and tried various in-game settings but it always hangs. Any ideas?