For some reason my 360 has decided not to show using a hdmi cable. It was fine yesterday morning but when I plugged it in again last night it came up with "invalid format" It's been tried on another tv and it has the same problem. ( this time it says "over range" ) I've tried another lead too. My sons 360 works fine so I know its not the tv's. With the component cables it work also. The Tv's are not 1080p but the xbox is set to 720 or even 480 ( through component ) and its the same thing. Anyone had this ? The Xbox is only a couple of months old.