Anyone else notice that a lot of the premium channels are NOT passing through the Dolby Digital signal thru the 5100 when they are being broadcast? I notice this with Encore (E & W) and the multiplex Showtime channels (SHOX, SHOC, SHOW, SHOT, Flix, etc.). At the beginning of the movie on these channels, they say it's available in Dolby Digital 5.1, but Comcast isn't sending the Dolby Digital signal through. They only seem to send it for the main HBO and Showtime channels. thanks.