The other thing that can cause problems is the way your house is wired. Believe me, I'm no expert in this area at all, but my understanding is sometimes houses are wired with separate circuits (probably not the right word) that make 1 half of the house totally separate from the other. I'm sure that someone with more experience (that actually knows what the hell they are talking about) can add more details, but I wanted to throw out another potential problem.
Let's see if I can explain this...
Residential wiring consists of 2 "Hot" wires, 1 "Neutral", and one "Ground". At the breaker box, the ground and neutral wires connect to all circuits; however, the hot wires are split where one goes to either side of the breaker pannel.
What you have is essentially, 2 110V circuits providing power to all of the circuits in the house. The way 220V circuits work is by combining both sides of the breaker pannel.
Depending on how Dishcomm is set-up, it may need all receivers plugged into circuits connected to the same side of the breaker pannel.