My MacBook has been sleeping and waking quite erratically lately. Sometimes when I open the lid the screen comes on and then switches itself off. To rectify it I have to close and reopen slightly and jiggle the mouse around a bit then open fully. It's an intermittent problem though. I noticed yesterday however that even though my MacBook is at home with the lid shut, I can still access it through back to my Mac which leads me to believe it's not actually hibernating when the lid is closed. The white light come on at the front when I close the lid, but I don't think it's pulsing. Is this a feature of back to my mac or do I need to reset my MacBook's power management?