The splitter you are using may be the problem. Typically a 2GHz or higher splitter will pass the frequencies you're looking for instead of trapping or filtering them.
I did get 2 2Ghz splitters and when I connect them both downstairs and up in her room I LOSE the Signal for the DirectTv completely. The cable works GREAT but the DirecTV HD signal in case the whole signal disapperas and all I get is Searching for Sattelite Signal. Any other ideas.