Just a thought. Originally Comcast cable cards installed in a TiVo was only one way. Now, somehow, the TiVo premiere is able to send a request to select an Xfinity VOD program. Is this request sent via the coax or might it be going through the Ethernet/Internet connection? Could this thing with the GSM errors be the result of a bad or corrupt message being sent to Xfinity VOD via the Internet? Is it possible that the problem is not on the cable tv side but on the Internet side? Does anyone know if Comcast made some Internet modification recently?
I just did a quick test. I disconnected my Ethernet cable from the back of my Premiere 4. Then, when I tried to get any video on demand I get a "network is currently unavailable" message. Now, not every Comcast cable tv subscriber also has Internet service, yet they get VOD. My stand-alone HD cable box has no Internet connection, yet it gets VOD just fine?