I've had my Roamio Plus for a few days (almost a week) and I am seeing an issue when changing channels. A lot of times the channel won't tune at all. No error comes up, just a blank screen. A small percentage of the time, if I channel up or down, then back, the show will tune. Most of the time, nothing. I was just watching a movie on Cinemax, changed channel, then back,and poof, black screen. This happens on standard cable channels, as well as premiums. I don't think I've seen it on "free" channels, so this must be to do with the cable card. Would you guys/gals agree? Who should I yell at first, Tivo, or Time Warner?