Now that I have a Mac again I tried this. Everything I tried worked fine. I don't have your exact setup though. You could try to update to 10.6.5 and see if that helps. You can also try to run in a window and see if that is better.
Depths of Peril, Kivi's Underworld, Din's Curse, Drox Operative, Zombasite, Din's Legacy, & Drox Operative 2