I am new to Macs. I've had a late 07 MBP and now have a unibody MBP. Both go to sleep when I close the lid and wake up when I open the lid. Very rarely, when I open the lid, the screen stays black. All I do is hit the spacebar, and the MBP wakes up (I guess it was really tired?).
It has to be a problem with your computer or an application that is causing it. Maybe you should call AppleCare?
It has to be a problem with your computer or an application that is causing it. Maybe you should call AppleCare?