I bought a new 13" macbook pro today, 2.7GHz i7, but it has randomly shut down on me 4 or 5 times now, in the 10 hours that i have it. The first time was when i was setting up the mac when i first booted it up. Then i just assumed faulty OS install, i put in my vertex 3, installed the OS on there, but it happened a couple other times. Can i fix this? Should i return it? Thanks!