Have you tried the Xbox 360 reset display method? If you dont know...
1) Remove disc from tray
2) Turn Xbox off
3) Turn xbox on USING the wireless controller
4) While its booting up, press and hold the Y button, then press and hold the Right Trigger. Continue holding down both buttons, until the console resets again.
5) If you did it right, it should re-reset the console, in turn resetting the display of the console, back to 480p through the HDMI, then you can edit the display from there.
*it may take a few tries, but good luck
http://support.microsoft.com/kb/911059
If you already did it, I can't think of anything else
EDIT: Edited a few things for clarity
"Being single is easier on the gaming life, and the wallet."








