As I said, apple care seems to think it's a PMU issue, so you might as well try their instructions for resetting that. I still don't know if the one time it got all hot and shut itself down is related to the other times that it just won't wake up from sleep. The last time it did this, as I said, it had been asleep, but then the sleep light went out and it wouldn't respond. I know I hadn't shut it down absentmindedly because it was making some noise. Weird. I still haven't called applecare again because it's working okay now, and I just don't have the time- maybe this weekend.... Anyway, good luck ccr. Oh, by the way, I've also noticed that sometimes the ibook gets confused when the screen is closed part way, but then space bar is pushed. It'll wake up, then go to sleep when the screen is fully opened. I guess that's to be expected with any laptop set to sleep when closed, but still, I wonder if there's more to it.