Bought a TiVo series 3 for use with my Comcast digital cable. We've been using a Series 2 DT for a while, but the IR blaster occasionally drops channel changes and we wanted to try HD. So I set up the box and requested CableCARDs. A tech came out yesterday, tried to set things up for a couple of hours. No luck. The back up on authorization "hits" was at 30 minutes when we started, and soared to over an hour, so the tech requested the authorization and headed out (I had places to be). Turns out the folks on the other end had a number in a wrong field so nothing was going through. This morning on the phone they fixed their end and tried again. I got a couple of 161-4 messages, which are apparently considered a good sign (the cable system and the card are speaking to each other), though apparently seeing more than one isn't a good sign. No luck seeing any channels, and the cable card status screens don't indicate authorization. This afternoon they (two this time) came out again for a couple of hours, tried a different card. No luck. They tried to get through to the "addressability" department, but I gather things get jammed up in the afternoon and they couldn't get through. They did verify that the signal level was fine. (It was actually a little high, so they put me back on the splitter that I had removed earlier in the morning.) So they're coming back out tomorrow, with a stack of M cards and hopefully better luck getting through to the head-end folks. I had no idea it was this hard to get a CableCARD working. One of the techs said sometimes they'll go through half a dozen before getting a working setup.