Currently have 3 HD recievers in my house and trying to add a 4the reciever. The 4th reciever is the standard reciever D12-300 that I recieved when I originally got my service. I'm trying to activate this 4th reciever and all I get is "Searching for satellite signal" All lines are connected properly so I tried moving this reciever to the living room. I disconnected my working HD reciever and hooked up the standard reciever and get the same thing "Searching for satellite signal" I disconnect it and reconnect the HD box and it works fine. What am I missing here. The HD box works but the standard box will not. I have two of the D12-300 recievers and they are both doing the same thing. Are these not compatable with the new slim line dish.