The cable going to the HD TV in the living room, doesn't it have some type of set-top box or are you using a built-in tuner in the TV? Best I can tell this applies to you:
I made some assumptions earlier that evidently I shouldn't have so sorry about that. I've got DirecTV and I have a set top box, I've got an ANT input on the receiver for OTA and another input for Satellite. The receiver connects to my 42" Plasma monitor over component YPbPr.