I just purchased a Pioneer PDP 4360HD plasma. I also have a new Directv HD DVR. The DVR allows you to switch between 480i/p, 720p, and 1080i. For some reason, my DVR will only allow 480i. When I attempt to switch that, the screen goes blank but the audio remains. I have searched high and low looking for the current resolution of the plasma and how I may switch it but to no avail. Any suggestions on how I can "upgrade" to 720p? I have attempted to do this on several HD channels and nothing seems to work. Directv technicians were of no help. Thanks