Thanks for purchasing a Samsung.
You might check to see what resolution the box is sending. You can do that by pressing the "INFO" button on the remote. It will tell you what resolution the incoming signal is. If it's 480i or 480p, you may want to adjust the cable box to send a better signal. Often times, judder is the result of "not enough" picture coming in, and then the television has to upconvert the picture, which may cause the problem.
There is also a judder control in the menu options. You might want to adjust those if you're using AutoMotion Plus. For some inputs, turning off AutoMotion Plus processing will fare better, and again, this has to do with the input signal.
The final possibility is that if the cable company has a heavy signal compression, that may also cause some judder as the picture is decompressed. Unfortunately, it's not possible to know if this is the case, but usually the other two options will eliminate, if not substantially reducing the judder effects of high compression signals.
Just got a new Samsung 8000LED, when I am on cable, I have Time Warner digital cable in Austin. I notice there is a slight vertical jitter, you can see it very much so when in the guide since there is text and can see it moving.
Is this a known issue? Is there any setting that can fix this? Driving me crazy.