Thanks!
The cable card allows me to ditch the HD receiver (and also saves me $5 per month). It is true that with the cable card, my cable is not "interactive" with Comcast. There are no on screen channel guides, simply blank/black screens (I haven't figured out how to delete these channels (ie. pay-per-view channels) from the channel selections). I was told that if I wanted to order something I would have to call Comcast directly.