Advertisements I called Comcast to activate their two 3D channels and after over an hour on the phone they tell me that my Tivo 3 is not compatible with 3D. I have him log onto his own Comcast website where it shows a picture of all the DVR/cable boxes including my Tivo 3 box as a compatible device. He talks to his supervisor and they also say that I need a new Comcast box and that the Tivo 3 is not compatible. Says when he puts in the code to activate the 3D channels it gives him an error. Anybody have any suggestions.