Help with multi-switch - DirecTV DVR

For Help with multi-switch, relating to DirecTV DVRs and receivers. I just my RCA 4x3 model D6530 multi-switch. I have a dual LNB dish with one line going upstairs and one going to my Hughes DirecTV Tivo DVR downstairs. How do I need to connect to the multi-switch to make it work. I think I have tried every possible combination. Any ideas?