I can't believe the problems that Lion is causing everybody - we or should I say I didn't have any problems when I went to Snow Leopard. My iMac (early 2008) with second monitor and external HD for time machine won't sleep at all. I usually schedule mine to go sleep at 2am - it ignores the scheduling? If I manually (apple>sleep) the screen goes sleep but not the machine? Normally I don't have to do anything and it sleeps soundly and my external HD stops warring, light goes out and peace in the room but since lion the iMac won't sleep and the external will not stop warring / keeps its lights on I have tried normally with all my apps open - no good! I have tried switching all apps off (fast switch>Cmd+q) so only finder shows and then Apple > sleep but only the display goes sleep !!! I do not have internet sharing ticked. What can I do - have I got to Shut Down every night now??? I thought sleeping was the best thing for it - it's slept everynight since new and I love it to bits but was is going on???? NB My Macbook Pro - will still go to sleep manually.