Ghosting would usually show up on a tv that had an airial or on analog cable with the locals mostly. You stated that you moved the offending tv downstairs and it lessened but not completely, is it showing up on the other tv as well? Those signal ratings are good and not indicative of a coax problem either wich the ghosting would not be caused by a bad line from the dish to the receiver. Ghosting can also be caused by an external terristrial source such as a ham radio, microwave source or a radio system such as police, ems, utility, cell tower, ect ect so take a look around to see if there are any new towers up in your area or a neighbors. If its specific to one tv then try swapping the receivers around to see if it follows.