I recently bought a Xbox console. I connected to the TV directly and works fine. But I guess I am not getting the 720p, since my TV is only a HD Monitor does not have tuner in built. I get excellent reception on any HD channels from my cable box that has a HD Tuner. Now if I connect the XBOX to my HD Cable Receiver, will it upconvert and relay the signal to my TV as 720p? If yes, how do I change the channel settings on my cable box to send XBOX signal and not cable signal to my TV?