I have a customer who has 2 811's. It worked fine for about 2 months and then started to have problems. The problem is that one reciever will only pick up 1 satellite during a check switch (they have a 121 superdish, dp34).The other reciever was fine. We have replaced the reciever, replaced the cable from the switch, replaced the switch, the signal is fine on all transponders, voltage is fine, tried different grounds, and tried no ground. The odd thing is, is when we disconnect the sat. in cable from the good reciever the other one will pick up all three satellites, but when you hook it back up the bad unit will only get one again. any ideas?