hi folks, i have searched the forum for macbook pro sleep problems and there are many threads. But i didnt find anything related to MBP not sleeping after some time of inactivity. In the energy saver pref pane, you set the time you want the mac to sleep if inactive. No matter how many minutes i put that number, the MBP wont sleep. It sleeps when i go to apple/sleep. Or option+command+eject or close the lid but it wont autosleep. EDIT: I already did the SMC thing and repaired permissions with no luck. This happened after replacing the hard drive with a WD scorpio. But i dont thing it is hardware problem as software controls the autosleep action. EDIT: i am running osx 10.5.2 EDIT: The problem was caused by a software called You Control 1.6.1 and uninstalling the software resolves the problem.