Summary: Something happens when I choose a Comcast "On Demand" item that apparently causes the [powered up] 510 to block the HDMI signal going to the TV. The TV reports that the signal has been lost.
Details: I choose an On Demand selection and hit "Play." I get "one moment please," then the screen goes dark and I see the time bar at the bottom of the screen for a brief second. Then I lose all audio icons on the 510. I then get a "signal lost" error message on the Samsung TV. I also see the HDMI "pass thru" icon turn off (briefly), then on again in the 510's display. The audio icons do not re-appear - so no video, no audio. If I unplug then insert any of the HDMI cables in the config, the video and audio come back. If I turn the 510's input knob to DVD, then back to Cable STB, the video and audio come back. I bypassed the 510 completely (see config below), went straight from the STB to the TV, and I don't seem to have the problem. It seems like there is something that comes down the wire that hangs the 510 enough that it will not pass the HDMI signal through the receiver.
I have a Pace RNG110. HDMI out from that to the STR-DH510, then out to the TV. I do this so I can get 5.1 from Comcast (per the Samsung manual), as the TV does not output 5.1 if I go from the STB to the TV directly.
When I lose the signal, I also lose the remote's functions, except for powering off the Pace. Funny thing - the power light goes off, but the HD light stays on! I am unable to turn the STB back on until I "unjam" the system by unplugging/reinserting an HDMI cable or fiddling with the 510's input knob. Now I wonder if there's a bug in the Pace box.
[EDIT] Turns out that, when I turn off the STB (per above paragraph), the power light goes off, but the box is apparently not off. If I unjam (per above), the power light comes back on (and AV is restored). I have not touched the remote!
I have not experienced any other video or audio issues with regular channels - SD and/or HD.
I plan to do some more experimenting, but I wanted to get this out in the event that it's either a known problem or a cockpit error.
Thanks in advance for any ideas on this one. I'm stumped...
[EDIT] Looks like this is only a problem with On Demand HD content. So far, I can't make it fail if I choose content that is in SD.