I, too, am battling "mild" pixelation. Am about to write down the frequencies of the offending channels, but definitely showtime, starz, cinemax, and to a lesser extent HBOs. I notice it often on golf channel, but haven't really caught it on locals or the news channels. Time Warner has replaced the coax from the pole to my house, and I've swapped out the cable card and tuning adapter.
The pixelation is often multiple horizontal "bands" of distortion. My signal is generally 90 to 92, with snrs of 36 or 37. Probably normal, but staring at the diagnostic screen, the number will bounce from 90 to 92 to 90 ,etc every few seconds. They're sending out a tech again on Saturday to do more testing , and are potentially going to leave me with one of their dvrs to see if problem persists with theirs.
Is there any definitive solution to this? Any feedback to help me eliminate this pixelation is appreciated.