ok well it not the broadcaster signal.

I also watched Victoria Secret Fashion Show in HD on my HD CRT TV and I didnt see any pixelation, and I had it recorded on my DVR so I went back a few times to check. lol

Anyways if you dont see any pixelation on still or none motion pictures the picture settings on the TV should be fine, this maybe a LCD thing, you might try playing with the 120hz setting in the menu and see if it helps by turning it off or on.

As for HD channels the only one I seem to have a problem with is A&E channel and TBS channel and it not pixelation its just crappy color and sharpness.

hope this helps
good luck