I have the same problem, pixelization and artifacts, with the WCBS-2 HD feed from the 103 satellite.
I upgraded to the H20 + AT9 5LNB dish about a month ago, and the NBC-4, Fox-5 and ABC-7 in HD are appear slightly BETTER than the original HD feeds (82, 88 and 86).
The CBS-2 HD feed looks like CRAP compared to CBS HD on Channel 80.
My H20 shows the following signal strengths for the 103:
Transponder Signal-Strength
6 97
7 77
14 92
15 88
Anybody know which transponder CBS-2 HD is on? I suspect it might be the one with the lowest signal strength, but it would seem that with a digital signal there shouldn't be any difference in PQ with a signal in the 70's vs. the 90's.
D* customer service was no help at all, they told me the HD CBS is only on channel 80, channel 2 is SD only. When I pointed out that I have 2 channel 2's (SD +HD) they thought I must be talking about the west-coast feed!