I think what you are speaking about is the nature of a rolling shutter system, such as the D7000 and many video camera have these days:
Judder and jiggle-shutter are un-related, but they come about through the same mechanism... panning too fast. Jiggle shutter occurs because the sensor output is read top to bottom. When you pan very fast, the frames are not read out fast enough before the scene shifts, so the final image is distorted because pixels are recorded at significantly different points in time and frames of reference.
Judder is different. There is no distortion in the frame, but it looks like frames are skipping during the pan, or the motion isn't smooth. The root cause is because the camera isn't sampling or producing data fast enough to maintain the illusion of motion. A more involved explanation is because the fps of the input and output devices aren't synchronized. Think of it as "the moire of motion". You can mitigate it by using a slower shutter speed so that some blur is recorded and by carefully matching your shutter speed fps to your intended output format.
In both cases, the easiest answer is to know the limitations of the camera and don't pan faster than comfort level.
|Fangorn Forest by cand1d|
|Yosemite Falls with Moonbow by Jonathan Shapiro|
from Best Landscape of the Week 4