I wanted to post an update to my issue. Just to recap, the TivoHD I originally had obviously had one bad tuner. This explained why some shows were fine and others were crap. After a lot of testing, I discovered that one tuner was always the one with pixelation. If you are having problems, make sure you isolate if it is happening to you on just one tuner or on both. I thought my problem was with my scards, but after switching them out (over a long and trying period with techs), I switched out my TivoHD. Now, I have no problems at all. All pixelation is gone. Occasionally I will still get a scard "hiccup" where one of my cards thinks it is not activated, but my pixelation issues have been gone since changing out my box.