I have an iMac G5 17" that will not put itself to sleep. If I press the power button, it will go to sleep just fine. But if I set it to go to sleep after an hour of inactivity, the display will go to sleep, but not the entire mac. Even when I set a schedule for my mac to go to sleep at 2:00am every night, I still wake up to find it blowing and whirring - wide awake. Anyone have any ideas about this?