According to C-NET Blogs:

"Some users of Windows Vista Media Center say they were blocked from recording NBC Universal TV shows American Gladiator and Medium on Monday night..."

"Restrictions set by the broadcaster and/or originator prohibit recording of this program," the error message read."

"...Some users of Windows Vista Media Center say they were blocked from recording NBC Universal TV shows American Gladiator and Medium on Monday night."

The article went on to say... "On Tuesday, the cause for the block of the NBC Universal shows was still unclear. Representatives from both the network and Microsoft said they would need time to look into the matter."

"Until they do, here are the few available clues. Most of those who posted at Greenbutton were Vista users recording digital cable with ATI cablecard tuners. "

".. Jessica Zahn, a program manager in Microsoft's Media Center TV group, who according to Greenbutton has volunteered to answer questions at the site, apparently responded to Alex (a Microsoft spokeswoman said she could not confirm the message came from Zahn). The person who responded under the username JessZahn said the problem had either one of two causes. "...

"...The broadcaster is setting the 'Copy Never' flag and Media Center's behavior is expected or Media Center is misinterpreting data it receives," and someone at Microsoft would need to study the stream of the show to know for sure..."

Don's Commentary..

This does not bode well for the future of Media Center PC's especially those with the new CableCard Cable tuners.  Even if this was a mistake the fact that it was turned on, spells the posibility of problems in the future with fair use and the ability of broadcasters to restrict content at will..

If you don't believe in this, you should write your congress people and the FCC and COMPLAIN!