I also had this issue... but have since switched to a graphics card to make the problem disappear. My current system for this is an i3-2120 on a GIGABYTE GA-Z68AP-D3... but have also tried it on various others that have crossed my way. Throw in any card that supports hdcp and it just works take it out and it doesn't. 90% of the time it gets a blank screen with audio on the protected mpeg4 channels and the other 10% the not supporting playback of protected content error, or nothing. Since I now have lots of protected content recorded, I have been reluctant to remove my graphics card on my main system in case it breaks playready. I also believe that since this probably affects fewer than 1000 people, personally I believe <100, as they must have a sandy bridge (or ivy?), use integrated graphics, have a cable card tuner, use cox in phoenix, and realize they are actually supposed to get those plus package channels, I honestly don't expect companies to spend much time getting this fixed unless it would also affect a device like the Q (if it is planning on using intel integrated graphics) as everyone I know with a cable card tuner also would have a dedicated video card for gaming and the problem wouldn't show up for them.
This friday I should get a new hard drive and a second monitor that should allow me to play around some more with it. I intend to make a new windows installation, try it without a card with various drivers. I will then install a graphics card. At this time, based on past experiences, I will now be able to play the channel. I'll then attach the 2nd monitor to the integrated video and see if it can play the video on either monitor (I will also test with intel as both primary and secondary, but may have a problem using both graphics).
If there is anything else you would like me try to confirm/refute this bug let me know... I'll only have access to the mpeg4 hd versions of hub, diy, cooking, outdoor and swrv as I no longer get the premiums. I willing to do packet captures or anything else but since the channels are marked copy once I don't know if they will do any good. I would also like to know if you think I should install any other codec/filter package... previous problems with media center tend to make me not want to install 3rd party packages as they tended to "break" media center but since this isn't intended to be a real machine I don't mind installing something that might break media center..
For a two hour period on saturday, I couldn't get diyhd or cookinghd to come in... as it said channel didn't exist on cable system... I'm a little curious if this was the window they got their stream captured. I'd also be curious if they were to remove the copy once flag if it would work.
About a year ago I read an article of how intel was using open source... one of the things brought up in this article was how they used an open source project to process h264 more efficiently and would be including it in their sandy bridge drivers... as I was reading it, I remember all I could think about was how that open source project would always break vista media center (I want to say it was lav but it may have been another one) I've been trying to find the article but now all searches with related terms result in Eric Gur's quicksync project, and this was more of something to be included not a separate install. The original article was more an article on intel using open source but I can't remember if it was an "in a good way" article on how they were embracing it or if it was how "evil they were" for not properly recognizing the original project (note: I'm not saying they are/were evil just that the article might have) the only thing that stuck in my mind was it was for h264 and the original package mentioned had given me problems in the past with vista... at the time I "knew" it wouldn't affect me since I thought I would never use intel graphics... but when my motherboard for my q6700 died, 2-3 months earlier than a planned upgrade, I had to get a system built quickly and cheap.