Hello all- it's been just about forever since I've posted, but something has happened that I just can't be quiet about. I bought an i7 15" MBP in May, and long story short it began having an issue in January. After several hours of being on, under any use, it would shut off the screen, become unresponsive to keyboard or mouse commands, and leave the power LED on. One time, it even left the iSight LED on when it did this in the middle of a Skype call. Fast forward to today- I'm on the 3rd (yes THIRD) logic board, and just performed a fresh OS X install and update to 10.6.7 as per my local store's recommendation. They thought this would solve the issue. About 5 minutes ago, it did the SAME thing it always has. What do I do? Bite the bullet and go for board four? (Or perhaps another assorted repair) Or ask for a new machine entirely? 
/rant
Thank you guys.
/rant
Thank you guys.