Help I am using Broadband cable going to a splitter then to the Tivo & cable box -- cable box to TV. I can watch premium channels & hi end Chns. 100 & up normally on the tv without Tivo. but Tivo will not record any channels above 77 which is basic service. all I get is a black screen with a banner at the bottom "Searching for signal" when trying to record premium channels like HBO Tivo goes through the motions of recording, but when I go to view it there's just a black screen. Cable co. sent a rep. & changed the box. no luck! Could it be a Bad Tivo?