This happens quiet often.. I close my MB's lid to sleep and when i try to open the lid later to use the computer, it makes the superdrive noise but the screen stays off, I try that frequently, but nothing solves it besides restarting the machine by the I/O button. Today, after closing the lid and putting my MB in it's bag, thanks god, I decided to use it a little an hour later when I got in the car, to find out that the MB is all HOT and running, like if it wasn't sleeping. Sometimes, it just wakes up at the middle of night and then go back to sleep on it's own?! when I am home i just leave the lid open and put it in sleep mode, since i connect it to an external keyboard/mouse. Anyone got a hint? anything i should be aware of? PS, i am on leopard, specs in sign. Thanks.