The GeForce 9600M GT is known to have this problem, and will be included in the list of cards that need the fix in a future game update (along with the GT 120).
You should be able to get the game working by using the following command in the Terminal:
defaults write com.larian.dos ShaderBasedClear -bool true
BTW, UBBCode is disabled for new accounts, to try to discourage spam (no clickable links). You can now use UBBCode, and will not need to use captchas to post, etc.
