Just upgraded to Dish HD with a new 47inch HD TV. Trying to figure out where the 5.1 audio is. I've tried two setups, using the optical output on the HD (VIP622) to the optical input on my Onkyo 5.1 Stereo Receiver. I've also connected the optical out on the TV to the stereo and in either case, I get no sound to from the receiver. (I know the cable and receiver are good because ...