Swapped out a single tuner Series 2 with a new DT Series 2. Matched up the cables exactly but still not getting a picture during Guided Setup. Cable box is HD but I'm not ready to buy a HD TiVo. Is there something about the dual tuner that requires a different cable configuration than the single tuner model? I suspect so but am not ready to go all willy nilly while I still have only a small set of variables to mess up. The connection is RF and the wireless is working fine, fwiw.