I noticed this ever since I got my new Athlon XP. If I take off to work leaving my computer on the ambient temp is usually about 85 degrees in the room when I get home, but when I turn it off before I leave its usually about 79 degrees. I also live in So Cali so that doesnt help w/ temps, but Im just wondering if any of you other people have the same thing happening when you leave your comps on. I dont even have an exhaust fan, I think that might make it raise a degree or 2.