I just installed the DirecTV AM 21 receiver for my off air HD signals due to upgrading HD receiver and have been having audio problems with both the off air and DirecTV HD audio ever since. Mainly it has been with the commercials, but this weekend I could not hear the audio feed for the Ryder Cup while watching it in HD. Tonight on SNF, I am still having the same problem, I can hear the game, some of the commercials, but not others. Needless to say, besides being very annoying, it is driving me crazy. Can anyone help me understand what is going on!