Hi - I am on my 2nd xbox360 after the first one froze then crashed, causing the dvd drive to no longer think it was part of the system.
As far as I know there was a bad batch of xboxs, if yours crashes and when you plug in a controller, the ring of light is on the opposite side it should be, then theres problems. Same applies to if it sometimes takes two goes to turn it on.
You can't place them on a carpet either, but there is an xbox360 fan cooling stand you can buy from www.lik-sang.com