2 Questions Regarding Channel Lineup and Blank Screen Message

Have a series 2 dual tuner 80 hour tivo. I noticed that every channel in the channel lineup settings are listed twice, giving me the option to choose either "box" or "cable". Which one should I select and what is the difference? I have a standard HD cable box that is connected and am using the RF splitter, IR cables.

Also, some shows are recording and when I go to play them back, I'm getting some message saying that the hdmi/dvi input is blocked...or something to that affect. And all that shows is a black screen with that error message. What does it mean? Thanks.