I am getting no sound output from the HR20 to my harman/kardon avr 300 receiver. I know my sound receiver is okay, dvd plays great. I bought new optical cable cable today, thinking maybe my old one was damaged. Still no sound. After one hour of talking to DTV, they told me my cable had to specifically say for dolby digital. I will buy another cable, but want to make sure this is right. Has anyone else had a problem with no sound output? (sound is fine through the audio on the tv - audio cable hookup. Any help greatly appreciated.