Wondering if this is happening to anyone else: My new MBPr 13" (base model 8/256), purchased just over 2weeks ago, has shutdown 3times now on being woken from sleep. tells me: your computer shutdown because of a problem. I did Permissions repair each time. Talked to Apple Support today, did SMC and PRAM resets, I knew about those, also did Safe Boot, which was new to me. The tech guy thought it may have happened because I plugged in an external drive while it was asleep, as I was going to do a Time Machine backup. I can't remember if I had an external drive attached the other times this happened. Haven't had time to test it again since the resets. Wondering if this is happening to anyone else, with or without anything external plugged in?