I've taken lots of 3D with my Panasonic 3D1 and Sony TD10 and have looked at other youtubes (many of those on this forum) of the same cameras and other 3D cameras. During pans, they all have the same weird stutter. It is not consistent with the shutter speed or frames per second. What I see is about every 2 to 4 frames there is a jump creating a very uneven stutter. Even when the camera has no movement, but the objects are moving (e.g. people), they move with an inconsistent stutter or judder. When I watch pans in 24hz commercial movies, I don't see this. Rather I see a consistent movement.
I am assuming that what is happening is the stabilizer in these noncommercial cameras is holding the image for a number of frames, then letting go for the next number of frames and so on.
I thought it might be the rendering software used for the videos, but I see this just looking at the output from the cameras. I understand that holding the camera very still and an extremely slow scan is the answer, but it doesn't explain the phenomenon I'm seeing.