I noticed that at times my picture has diagonal lines and it seems to come and go. I use D* and they said it was a loose connection but all fittings seem tight. I have a 721 with some sort of a switch to utilize both tuners in the 721. It is a samll aluminum looking box with at least two out outs and I think it even has the capability for one or two more. I am using the dish 500 with a dual LNB. I was wondering if anyone else had this problem and if they did what the fix was, I just wonder if my switch has become wet or something. It is located outside on the same pole as my dish. I wanted the installer to put it inside but he said that this was the way to install it so I didn't argue. Bob