I own an expensive two year old Denon AVP-A1HDCI AVP. Quite recently I have been intermittent messages "This TV does not support HDCP" when watching content on HBO. This only happens when watching HBO through the Denon via HDMI.
I spoke to Denon and they acknowledge that Denon has a problem here.
I am not sure what to do about this because Denon says it is not their problem in spite of the fact that it only exist, at least for me, when watching HBO content through their AVP. All my 4 of my other sets do not have this problem.
Well ... I see it occasionally on my 3808 when switching channels (involving a resolution switch.) It flashes once, then goes away, it doesn't seem to affect actual programming. It's not a real issue for me, it looks like a brief glitch in the handshake.
I do have "native" resolution enabled on my D* DVR.
The Panasonic is the only TV connected via the Denon to the Direct TV receiver. When the Denon is off I have no HDCP issues or messages via the HDMI. It only occurs when the Denon is on and only very briefly and intermittently.