My premiere projects keeps freezing and I can't seem to figure out why. I'm not doing some crazy rendering or anything. Basic edits. I open it, work anywhere from 10-20minutes and it stops working and I have to force quick or the beach ball spins forever. I think it's my 5400 rpm hard drive... I'm running a late 2011 Mac book Pro Processor 2.2 GHz Intel Core i7 Memory 16 GB 1333 MHz DDR3 Graphics AMD Radeon HD 6750M 512 MB Any clue?