Received a new HR21-100 from DirecTV via drop shipment when my old Hughes quit. I already have another Hr21-100 on another set and a Slimline 5 dish. For whatever reason, no BBCs were included in the box of the new receiver. After connecting, I am only receiving certain stations. Called DirecTV and they said I need the BBCs. Here's my question(s): Does that sound correct? Also, the new receiver is hooked up to a SD TV, so are BBCs even needed for that set?