It's definitely TWC, when I had them out (they wouldn't let me P/U the box) to install extra Signature box (Whole House) the installer said my signal was too strong and he stepped it down via splitters???
No problem with BD, Just regular TV, especially Live broadcast, like the SuperBowl & Grammys, almost unwatchable.
I'm gonna call them tomorrow and give them one last chance, if I don't get the results I expect, then I'm gonna try DTV.
I don't know if a stronger signal is the fix, I suspect they are compressing the main feed to squeeze all the channels they now offer??