Art,
Check the cable that you are using. Is it RG6 cable?? IF not it probably says RG59, which does not have enough surface area on the cable (bandwidth) to carry all signals.. Check the cable.. if it's not at least RG6, rewire!!! Best cable out there to use?? Monster Cable ISAT reference coax cable.. Tightly wound braided shield, copper/aluminum foil shield, and NO2 injected dielectric.. i have this stuff running my 4 room HD satellite, local to local, and off air signals!!! Email me for more info!!

John