Help! The HD channels are not coming in HD..... I have a Comcast cable Motorola DCT6412 III and the HD channels were coming in fine a few days ago. I think it may have stopped coming in HD when I went to composite instead of the coax cable. Did I accidentally hit something? I have a 32" Sceptre Komodo LCD. I get the HD channels, but they are not in HD format... they have black bars on top and bottom and are in 480i.