I called Cox tech support about my "incompatibility" issue...the woman told me that the installer was incorrect and that the Motorola s-cards should work with the TiVo HD. She suggested that for my next installation appointment, I request a technician who is familiar with the TiVo HD...this gives me hope. I then called TiVo tech support and got the same response. So, I'm going for my second attempt tomorrow. I'm crossing my fingers that this goes well. In the mean time, I've left the two TiVo HD boxes connected to my home network and to the televisions in my house (even though I'm watching analog) and love the MRV. After getting a taste of this, I'll be really bummed if these cablecards do not work.