I was watching one of my local channels this after noon turned to a differant channel, went back to the local channel all I get is a blank screen. If I hit the INFO button I get the PIP of what is on that channel BUT not when I go to The full screen on that channel. It is not working on only the main receiver DVR, The wireless receiver works ok. I get the ;ocal channel on the wireless receiver But not on the DVR receiver. Any ideas ?