I'm sure something about this has been posted before, but just in case anyone's struggling with the same issue, I figured I'd post what I found out. I have a Pioneer Elite receiver with HDMI capability and I wanted to run my Comcast DVR box through my receiver as my TV only has one HDMI input. (Adding an XBox elite soon and want to run that through the elite also) Anyway when I ran the cable box through the receiver I got an error message stating that the Comcast DVR is not HDCP compatible use component inputs and the screen turned green. After a lot of research and contacting Comcast it appears that the Motorola DVR I have thinks my receiver is some kind of HDMI repeater and shuts down the cable box signal.
I determined that my Comcast DVR has firmware revision 12.31 and the fix for this issue is apparently available in firmware version 12.35.(some parts of East Coast are running Firmware 16.35) Comcast has informed me that they are aware of the issue and will be pushing a firmware fix that should correct the issue sometime between June -September
Until then I
l have to use component for one of my sources and wait for the fix. Just thought I'd clue everyone in in case someone else is having the same problem.