Thought I'd throw this out for the wider LCD community:
I'm still bothered by "judder" on some comcast HD cable networks on my sharp 70C8470U. Since switching my receiver to output 1080p (onkyo 609), I almost never notice judder. BUT, i'm constantly perusing cable HD channels like G4, FX, AMC, MGM, TNT and occasionally find a movie that judders on motion.
With the receiver upconverting it's MUCH better than it was. A couple of weeks ago I tried to watch Transformers 1 on FX HD and it was horrifically juddering to the point of not being watchable. Note that this judder isn't like it's good for awhile, then juddery, it's more like speed-up, slow-down, speed-up, slowdown...
From thursday last week through the weekend, I checked out Matrix 2 on AMC HD which looked fantastic, War of the Worlds last night looked really good, but something I surfed onto last night (forget what it was last night) had some subtle judder in it.
I'm currently running movie mode with all enhancements off (film mode, motion enhancement, pixel plus, active contrast, energy savings,...).
What might I have set incorrectly to account for this? Might it be the specific HD cable broadcast? I've not gone to another set in my house to see if I can see it (like the panny 50ST30 plasma in the bedroom), but I'd bet it doesn't do it as i've never seen anything like this before.
My current theory is that it's doing some processing and not doing it well. I'm just not sure what it doing. The AVR is de-interlacing (1080i output from cable box to AVR, AVR converts to 1080p and outputs to the TV) so there should be nothing for the set to do but display it. I have read that the sharps default to 60Hz refresh rate when aquomotion is off. Is is possible that 1080p is not a native refresh rate for this set? (not likely) is it possible that 60Hz is the issue?
Should I use a different viewing mode? (hate to go this route as Movie is pretty darned accurate calibrated).
Any ideas how to get to the bottom of this?