just want to share my cablecard installation story.
i have a new tivo premiere and requested a cablecard from comcast. they said someone has to come out to install it. fine.
the technician installed an m-card and initially it was missing certain channels. missing channels included my premium channels and various channels like QVC, QVC-HD, ESPN, etc. I was getting FOX, ABC, NBC, CBS, PBS and all the corresponding HD channels. the technician was on the phone with comcast for a while and those missing channels showed up. however, after technician left, those channels were gone again. i called for technician to return.
long story short. it took another three appointments to finally get it right. by the fourth appointment, the comcast technician who came, jerry, instantly knew what the problem was when he pulled out my cablecard. he said that the m-card that they originally gave me is not compatible with tivo premiere machines. he said the "gold-tipped" m-cards (with gold-tipped connectors) will always work with the tivo premiere machines, whereas the other m-cards (i think both were motorola) will work one out of twenty times. sure enough once he put in the new m-card with the gold-tips, it worked like a charm (well he still needed to call it in to activate of course). he was also saying that in the cablecard conditional access menu, the Val field shold show a "V" and not a "?". The "V" shows the cablecard is paired. However, I think even when I had the bad card and the missing channels, I did have a "V," so I don't think the "V" told the whole story. It was the "gold-tipped" m-cards that did it.
hope this helps someone who's having issues with new cablecard install from comcast and missing channels.