I just got a Denon AVR-S750H (wanted one for so long, and made me happy!) and I have a very irritating black screen flash only when playing off the DVR (which is cable box also). Never get this with any other playback. Some shows it does and others it does not. I contacted Denon and they say it is the DVR to TV causing the issue and not the receiver. I have an old Onkyo that never had any issues with this same setup (over 2 yrs with this box and 10yrs total) so I am really confused. Said I could buy a $200 item that makes sure this does not happen. Anyone have any things I could try? I have replaced HDMI cables.