Has anybody got this problem where the new alu MacBook sometimes doesn't go asleep when you close the lid or select SLEEP from the shutdown menu? Basically i close the lid and it apparently goes in sleep mode, but then after 15 seconds it wakes up, the apple logo on the back flashes, the status light goes from flashing to still, it then automatically goes asleep again....15 seconds later same thing and so on in a loop. the problem is very intermittent, it may happen 1 out of 5 times I send the computer to sleep, I figured out that the reason for this could be software related as I don't have either Bluetooth or any kind of USB dongle attached to the laptop, but I can't really see any process running other than Finder. Any idea? is this a common problem, software issue? Hardware related?