So I installed it on my newer 2.6 GHz macbook pro and it runs MUCH better than on my 2.33 GHz. I really am not sure why this is. Both are core 2 duo machines with high end mobile graphics cards. There isn't anything running on the 2.33 GHz that is sucking CPU, and both machines have plenty of RAM free. The only thing I can think of is that it doesn't like the ATI video card in the 2.33. I do have boot camp installed on the 2.33 so I am going to try running the windows version on my boot camp drive and see if there is a performance difference there. How much would that suck to have the same game on the same machine run better on Windows than on Leopard.