Two weeks ago, I purchased two TivoHD units and I called to schedule my cablecard install appointment. I was incredulous that they couldn't get them to me until 8/10, but I couldn't do anything to budge them, so...there it is. The appointment was scheduled for 8/10 between 8 and 11am. That was yesterday, and nobody showed up. I called at 11 and was told the installer was behind but would contact me shortly. Hours pass. I call again and I'm told he will be there in 30 minutes. The deadline passes, I call again. I'm told 45 minutes. The deadline passes, I call again. All in all I call 7 times and nobody shows up, nobody calls me. The day is lost. This morning, 8/11, I call again relate my experience to the operator who says my installer will be out between 1 and 5pm. I am skeptical after all the failed promises, but I hang up and wait. So the installer finally shows up today around 3pm. He has 4 cablecards with him, and we get started. The installer wanted to plug up all four cards, *then* call them all in at once for activation. I can understand that to some degree, so we do this and he writes down all the numbers by hand. The first unit (Living Room) activates and both tuners appear happy. Success! I am starting to feel better about all of this. As for the second unit (Bedroom), card #1 won't seem to activate, but card #2 did. He goes out to the truck and gets a replacement. As soon as it gets plugged in, Tivo detects it as an M-Card (multistream) card! Yeah! I explain to him that this means I only need the one after all, so he calls in a cancel for card #2 on the bedroom Tivo, and we're done. He leaves. I have 2 cards in the living room unit and 1 M-Card in the bedroom unit. Then my living room starts throwing cablecard error messages. ARGH! I reboot the unit - the error keeps popping up and it seems random. Great. It's always cablecard #1. I pull it out, and pull out #2 (intending to swap them to see if the problem moves with the box) and...hey, card #2 is an M-Card! Great!!! (The M was obscured by a large sticker reading "1-way" otherwise I would have noticed this right off the bat.) So I put the MCard in livingroom slot #1 and now all is well. I just have to call time-warner and return the 3rd unused cable card. The S-Cards are red, and read "Comcast" on them. The M-Cards are pink and read "Motorola" on them. My only dilemma now is to figure out which channels to "hide" from Tivo, to avoid confusion when scheduling season passes. I have an antenna set up, so for any given local channel I am getting 4 versions. For example, FOX: - 4: The analog cable version - 4-1: The HD/Digital OTA version - 356: The digital cable non-HD version - 357: The digital cable HD version - 358: The digital cable "digital" version When comparing the 4-1 and the 357 version, they both look the same to my eyes, so in the interest of simplicity I may disconnect the antenna. Some experimentation and time will let me know one I settle on. (The same situation applies for the analog cable channels that are duplicated on the digital side, too.) In the end, I am gruntled. I got 2 M-Cards, so my cost (once I return the spare) will be $5.90 per month. The channel selection appears to be much wider than DirecTV's. ADDENDUM: In the end, the issue with the cablecard errors was related to how they were provisioned. The installer screwed up and transposed the card serial #s of the S and M card with the Host and Data numbers. (I am surprised it worked at all.) I am also very pleased that Time-Warner got my issue resolved on a Sunday afternoon! Both M cards are working 100%.