This seems like a simple question but I haven't had any luck finding the answer. We're dealing with a salesperson who gives us accurate info about 70% of the time. He told us that the line doubler in a TV (we're thinking about a Sony XBR450) will have no effect on the signal from DirecTv's main atellite (i.e., the sat that is accessed with the round dish and that carries most of their programming). He said that for the line doubler to have any effect we must be able to pick up the signal from the HD satellite (the one you get with the oval dish). Is this correct?