I have been trying to find a solution to this problem myself and I think I have found one.

The problem is 10.5.7 and above. Maya would crash in about 3 minutes for me, totally locking the mac as well - resulting in me doing a hard reset, which I am not a fan of.

After troubleshooting like crazy the solution is thus: down-grade. The video card drivers are not working in the systems 10.5.7, 10.5.8 and this creates a crazy Open GL conflict that bugs Maya out.

I downgraded and Maya 2009 is running smoothly. There is a lot of discussion (and a fair bit of anger) on the Apple Discussion boards as well about this very subject and it's not limited solely to Maya either. Hope this helps.