I jetted home, so that I could 'watch' the installer deal with the TiVo and fix anything that I thought was 'wrong'. In the end, though, our installer was great. The salesperson who took the order, though, listed me as needing only 1 CableCARD - the TiVo uses 2, and I told them as much. The installer, though, mentioned that he expected a TiVo install when he saw a CableCARD install and a DVR pick-up, so he brought two CableCARDs with him.
After installing the cards in my box, he then had to call someone (I presume in network operations) to 'authorize' the cards & my TiVo. That took a total of four calls. First, the tech called in to activate cards, but on the first call they could only take info from one of the two cards. The tech was then called back for the second card's info. The second card didn't get activated for Showtime, so the tech called back to get that fixed. We gave it some time, but it still didn't get fixed. The tech called back again, but this time seemed to get someone that he knew. A few more minutes and it was all done.
Minus one cable company DVR. Plus one digital cable connected TiVo. Yay!