I have recently updated to HDTV to go with my sony 40" 1080P television. When I first connected the new HD box from the cable company only a few of the channels workes including the analog channels. So I went back to the cable company, which was not a problem I work next door. Anyway they gave me a brand new box never used and all of the channels work most of the time. Some times many of the HD channels get glitchy and blocky. What I am wondering is if it is possible that I have a bad cable somewhere or if HDTV is just glitchy sometimes? Anybody.