I have two 522 DVR's with an intermittent caller id problem. Both receivers only show caller id info on about 1 out of every 10 calls. When the caller id info is displayed it displays on both units and when one does not display the info the other will not either. I know the caller id service is working properly from the phone company because it always shows on the phone. I have disconnected all of the phones in the house but it didn't make any difference. Dish support suggested a problem with the system grounding, but I have checked and the unit appears to properly grounded (dish to grounding block and grounding block to home electric ground rod) and all connections appear to be clean and tight. Any suggestions?