I recently connected a RCA DTC-100 HDTV tuner to my Mitsubishi VS-50803 50 inch HDTV. I have encountered an odd video artifact that I need help with. When using the RGB signal to view a HD channel, I encounter red background grays when switching to a regular DTV channel. If I switch back to the HDTV channel, the grays are temporarily red but sooon switch back to normal grays. Is this a result of poor BNC connectors/cable or a problem with the TV? I want to see regular DTV programming in 1080i which is why I'd like to fix this. (The RCA converts 480i signals to 540p which the Mits then converts to 1080i.)