Have a SD-DVR and some channels are coming in with lots of pixelation. USA, CNBC and others have really bad reception. Many of the other channels come in fine. DirectTV sent me one of their new DVR's to "test" with and these channels come in fine. Is there some reason that the Tivo receiver would have problems with these channels? I've swapped cables, and the issue is apparent off both receivers. I like DirecTV, and like Tivo, but want a good picture. I am thinking of buying a unit off ebay, but would hate to still have the pixelation if it's something with the DTV service.