Recently, my 15" early 2011 mbp has been having problems waking from sleep. The screen would come to life, as though it is waking from hibernation, with that progress bar filling up, and then it would literally fade to black in a blink. Shutting it down and restarting, I would get a blank grey screen for a couple of seconds before it goes black once again. I once went through a full hour of trying to revive it before it finally booted normally. This only started after 10.8.1. Any ideas lads?