Before spending money, the usual culprit is the cable or satellite input. Try running everything as you would like to (no conditioner, separate lines) but with the satellite input and power completely disconnected (from AC, pre/pro and display). If this eliminates the noise, your satellite antenna/receiver is improperly grounded and DirectTV should be required to fix it.
It's worth a shot.
Kal
It's worth a shot.
Kal