I have a Phillips FlatTV with a SA Cable Card for Adelphia. The HD channels have always looked perfect but the digital channels over #100 have always been pixilated. We have tried two Cable Cards with new TV firmware but both had the exact same problem.
The Adelphia tech is coming again on Friday to try two more Cards but he said they are the same model (only one choice) so I really don't see the point.
Last time the tech said that a booster wouldn't help because my HD channels are fine so the signal must be ok.
The TV upstairs with a cable box does not have any problems.
You need to call and ask to speak with a tech supervisor and see if they can send somebody out with a QAM analyzer to check the frequencies out that are pixilating. Just because your HD channels aren't pixelating doesn't mean there isn't a problem with the signal quality. The cable box upstairs won't indicate a problem because the chip set in the box is different from the chip set in the TV, they need to check the CNR on those frequencies to make sure everything is in check.