I've owned my brand new PM for about 2 weeks now and I've caught atleast 3 instances where the screensaver hasn't kicked in. All of these times I would not shutdown, and return two hours later to find the desktop still on. My screensaver is set to go off after 20 minutes of inactivity. Is there any reason for this. And no I don't have a cat, I don't live in an area with earthquakes and the house is't haunted. Thanks.