have you made the correct audio output selection from the right-side of the Audio TAB in the Settings Application(s)?
The left-side is automated and when selecting anything other than anolog, 'Same as Input' is correct for the left-side.
I have one computer that functions as both a media computer and a workstation. Attached to the computer are two display , a 1920 x 1080 plasma TV connected via HDMI and a 2560 x 1440 WQHD monitor connected via DisplayPort. Also, there is an AVR, the monitor has speaker and I also have headphone. I live on the edge of a HDCP violation and I think you are right to think you have a HDCP issue. Last night there was a storm that momentarily cut power while both displays including media center were running and on the plasma I got the following message:" Video Error Files needed to display video are not installed or are not working correctly. Restart Windows Media Center or restart the computer."
Restarting media center nor restarting the computer resolved the problem even after multiple tries.
This morning I stripped the system down the monitor running at 1920 x 1080 and a set of headphones connected to the computer and got media center working again. Then I added the plasma and AVR back in and then media center was working on the plasma again.
I have never tried the Shark007 codecs because I have gotten the system working the way I like without the codecs. But from reading Shark007 seems knowledgeable and many use his solution.
But what I wanted to say is that HDCP is a scheme the content producers created to protect their content along with the protected audio path. The software and equipment manufacturers built software and equipment which can play the content as long as the user keep his or her system simple. However, you with your extenders and me with my two displays and two audio sources live on the edge. When I fall over the edge and my system stops working the way I want I begin striping the system down to one computer with one display and one audio playback device. Once I have it working again I add everything back and it usually keeps working until the next unknown issue occurs.
So, what I am suggesting is to first try simple solutions others suggest. If the simple solutions don't work try simplifying your system until it works and then build it back up.
I'll try unplugging and resetting my Receiver and see if that rectifies the issue. I will also try to see if WMC work if I listen through some headphones. It could be that I simple have a bum HDMI cable as well. I try switching that out too to see what happens.
FWIW, I have no codecs installed (never have) and get the same error whenever my PC wakes. If I wait a few extra seconds before tuning a channel or playing a recording, I don't get the error. So I've simply made it a habit to wait. My theory is that some driver simply hasn't finished loading or the hardware hasn't finished booting. Ceton insists the problem is codec packs, but that's completely impossible in my case.
Well for what it is worth I got everything to work. I did a system restore, back to a date when everything was working and now it works. I noticed that while doing to restore a critical windows update occured also my 11 year old son is also on this a lot and he could have changed something with out me knowing. Having said all of this, I am good.
Thanks for the help all.