nordlead on 06 April 2009
leaving the system on when not in use just increases the amount of wear you put on the system, which will cause it to fail much sooner than it should (this goes for all electronics). It also increases your energy bill and is just wasteful for no reason. If you are walking out of the room and coming right back, just leave it on. But if you are going to be gone for 20 minutes or more, just shut the thing off.
Anyways, you obviously have a problem and should contact Microsoft for a replacement.
