I have a Panasonic HT-920 Home theater in a box. Lately when I change to digital in that is being broadcast in 5.1 the audio drops out and the front of the receiver/dvd flashes sometimes for up to a minute. You have to change channels to get the audio to finally come back on. What is causing this? Sometines it only does it for a few seconds and other times for a long period. Is there something I need to do? Can someone comment on this please? I am also hooked up with Comcast cable HD box with the cable box hooked up to the PAN 920's optical input. There is no dropouts when playing DVDs.