I have a Panasonic SA-HT17 home theater system hooked up to my Motorola 6412 Hd (Shaw cable) receiver via the optical out between the too. Rca mono audio connected from the Motorola 6412 to the mono TV audio. (TV sound all ways works.) On some HD channels I get no sound through the SA-HT17 surround sound.. when the TV program goes into commercials the sound comes on the surround sound! When the HD program comes back on after the commercials I get no sound again on the Panasonic SA-HT17. On some other HD channels I get no sound during the commercial but sound on the HD program. Other Hd channels I have no problem... I have tried connecting the Rca mono audio connected to the Panasonic SA-HT17 and the Motorola 6412 problem never changed... also when I have the TV sound on at the same time as the Panasonic SA-HT17 sound.. their is a time delay on one of the two sources... the two are not in sync and you hear an echo.. I have to turn one or the other off... I can't figure out what the problem is.... any help will be hugely appreciated!!!