My mac disagrees with Warcraft


There is something in my mac that quits out of games when im playing Warcraft 3 for no reason. It just quits me out of the game right at the start before i even see anything. It goes straight from load screen to end screen. Could this be some trigger i have to turn off? If anyone has any ideas please tell me. Thanks.
Have you downloaded all the latest patches for WCIII? Also, what OS are you using?
It gets worse the more I play it. When I dont play for a long time or a new version comes out it works fine but as I play the game more I drop almost all the time.