I've been having trouble with my early 2011 macbook pro going to sleep ever since I installed Lion. I googled it and it seems there are a number of possible causes: Internet Sharing --> but I don't have this enabled Little Snitch --> I don't have this installed Printer queues --> no printer either I have an external monitor that's connected. If I just close the lid of my MBP, the desktop goes to the external monitor and it doesn't go to sleep. When I have the external monitor unplugged and close the lid of my MBP, the computer just stays awake (I can heat the fans running after 10 minutes). However, if I click sleep from the apple menu, the computer goes to sleep fine (with or without the external monitor). But sometimes I forgot. I'm just used to closing the lid and having my notebook sleep. So sometimes, the computer stays awake for the entire night. Any ideas on how to make the computer sleep normally again? That is, I want it to sleep when I close the lid.