Back in December, I noted that Update Rollup 1 for Media Center Extender devices (not Xbox) was available.  This update fixed some bugs and added support for playback of TV programs using the CGMS-A broadcast flag such as HBO (no, it's not MS technology but we have to honor it). 

The good news is that as of yesterday, Media Center Extender for Xbox-customers can get an update to play back CGMS-A protected content.  The core update is available via Xbox Live for download , however viewing CGMS-A protected programs requires new Extender for Xbox discs. To obtain the new discs, click here (reg req'd).