My iMac G5 seems to shut down at some point when in sleep mode, and I have to unplug it and plug it back in to get it to turn back on. Just pressing the power button it reacts as though its not even plugged in. Is the some type of sleep plist or something I can check to see what the heck is going on? Better yet just do something to make it stop ! I'm afraid it has something to do with the electrical outlet so I have switched it to the lower one on the same plate, and got the same results. However I have a cordless phone plugged in to the other outlet on the same plate and have had no problems from it...HELP !