Same problem here, and I only just found this post. My system crapped out on May 15. Up until then everything had been working great with SP1 and 1.17 already installed. Dell XPS 420.
Since then I keep getting the Restricted Content Message. I can get mine to work by stopping the Media Center Receiver service in services and restarting it. after doing that the signal comes back. I post this cos this is an easy way for everyone to at least get it running for another 12 hours. Obviously the WAF has gone down to zero at this point.
I have tried many of the same things. Did a system restore to May 14 et al. None of it works.
I use comcast. I am convinced that this is not a cable company issue. Otherwise I would not be able to fix the problem by stopping and starting a serivce in Windows. This has to be a MS issue. They have done something to cause the receiver service to lose connectivity with the tuners or something each time the system goes out to do some sort of DRM check.
since the 1.17 worked fine with SP1 for a while I do not buy that this is a firmware issue on ATI end either.
You would think that MS could at least test stuff enough so that they dont mess up everyones systems. Just imagine how many people are out there who are getting frustrated with this whole exercise and are now going through multiple call outs of their service providers to get them to fix the machines.
And you want to know why the cable companies hate cablecards in pcs. I wonder how much they are spending trying to fix this problem which may not even be their problem
A frustrated user of Windows Media Center!