Comcast just gave me a new DVR (DCH3416) because the previous box (DCT6412) crapped out after they sent me firmware updates. The old box worked ok, some freezing, but I never had audio issues. With the new box, I hook up to my receiver using the TOSLINK (optical) audio, and hook up to my plasma using component.

When I change channels, from HD to low def (or vice versa) my receiver gets confused on what the signal is, and the audio drops. If i'm watching a recorded program, and I fastforward/rewind, the audio drops out. The tech tried 2 boxes, and both had the same result. He left saying, "I can't help you". Gee thanks.

The only way to get the audio back is to reselect the audio on the receiver. This is a pain. I think this is related to other people's issues using HDMI (no handshake between cable box and audio equipment).

Anyone know of a solution? Any word on firmware updates, Comcast tech support isn't helping.

My receiver is kind of old, I'm using the digital coax for something else, and I don't have HDMI, although it sounds like that would be a problem also.

Thanks.

I loose sound all the time when using the 30 second skip.
(especially, if you go fast)

So, I "exit" the recorded show.
When "live" I STILL have no sound.
I then "last" back to the recorded show and I have sound again.

I know your issue appears different, but the answer may work.

Next time, play a recorded show and see if you get sound back.

Welcome to the wonderful world of MOTO DVR's.
Like I always say... THings are "INCREDIBLY" better than 4 years ago.