Microsoft aren't entirely ignorant of the problems you've been having with your 360s. In a telephone interview with Reuters, Molly O'Donnell has admitted that Microsoft has "received a few isolated reports of consoles not
working as expected", pointing out that "with any launch of this magnitude, you're bound to see
something happening". True, but since nobody seems to be able to buy 360s, there are a surprising number of problems amongst the few that have made their way into homes.
If you're having trouble, the official line is to dial 1-800-4MYXBOX; Major Nelson also points out some web-based support documentation that might be of use.
