Hi, I've got 2 S-Card Cable cards from Comcast (Motorola). I also have an OTA feed that I'm hesitant to add to my TivoHD for fear that it will mess up the setup somehow with the cable cards at the same time. From what I know, the HD is a 2 tuner machine. Is it possible to add the 3rd source (OTA) in addition to the CC's and still have everything work properly? Thanks for your help.