I've tried searching the forums for an answer, so I apologize if this is a redundant post. My problem is shutting down my Air when finished and it boots back up when I plug it into AC power. I'm making sure it has completely powered off and once I plug it in, I hear the start up sound. It seems to be coming out of a sleep state when I open the lid. I'm running Lion, too. Any suggestions or ideas as to the cause?