Yet another service nightmare. We switched from a HR10-250 to the HR20-100 about 6 months ago. Terrible install with wires hanging over the roof and just a mess...but it worked fine. That receiver had a card issue a month ago and we were sent a HR21-700. We have since had an intermittent 771 error. It happens at about once a day and all we have to do is reset the receiver and everything is good again. After 2 missed appointments, the tech that came out today, says it is a line of sight issue. I've been a Directv customer for 7 years and have never had a line if sight problem except for the 119 sat, but that has been solved. A 771 error came up while he was here. I showed him that every transponder on every sat that we get shows a great signal. Still, there's a 771 error. He say line of sight. I reset the receiver, the channel that the error was on now has a great picture. Every channel I go to comes up fine. He says line of sight. Then he changes his tune a little and tells us that the person who did the original install must come back or they will get some sort of "back charge", and won't do any work today. He even had a receiver for us, but wouldn't take it out of his truck. We've been on the phone for over 2 hours with DirecTV and we're getting nowhere except a credit for our time. That's great and all, but I even told them that I was willing to pay whatever it took to get this right. They still won't listen. We are now waiting for a call back from DirecTV. Do you think that will actually happen??