I found a fix for this that worked for me. Dont ask why I tried it but it worked! I put a HDMI switcher between the cablebox and the yamaha HDMI input. I am not sure why it works but it does. The audio was actually clearer and the center channel responded better. An hdmi switch is about $25. Good Luck!
I have the same problem with a HK 5.1ch system, so its not a yamaha thing. I've been trying to find a fix but i haven't made any progress. I have a feeling Comcast just can't keep up with the bandwidth required for the box to output 5.1ch. I'm going to try running my video straight to the tv tonight and see what happens, but i doubt that wil so anything.
Had the technician out today, they determined it was a weak signal. Gave me the option to install an amplifier or schedule the maintenance team to come out and crank up the signal. I opted for the second choice. Hopefully this'll help.
Yep, same thing here. It reset itself back to auto and the sound become choppy. I checked on another forum and was told that one solution might be to connect the box directly to the tv, then run an optical cable from the box to the receiver for audio. That's what I'm going to try, I'll post back what I find out.
I switched the boxes, tried a different port on the receiver etc but nothing solved it.
I'm having the same problem, also on a (different) yamaha reciever. Setting to L-PCM did stop the audio dropout, but I've been told this limits you to 2 channel audio rather than 5.1 if the content supports it.
I'll keep an eye on it and see if it reverts back to 'auto' on my box too.
I purchased a yamaha receiver rx-v2600 and hooked my hd motorola box (small black one with no display) through a hdmi cable to my receiver then my recevier to my tv. Problem is my audio is cutting in an out. Its fine with my blueray player or if I hook the box up with the analog connectors but then I lose hd.
Now I fixed it by turning off the cable box and hitting menu bringing up the setup screen then going to additional hdmi settings and changing the audio settings from auto to L-PCM.
This fixed my audio problem. Now my problem is at least once a day the cable box converts itself back to auto and the problem is right back.