Thanks for trying. It seems like it only happens on one of my computers, whilst it works fine on another two (with previous Nvidia drivers.)
I uploaded a video to http://www.youtube.com/watch?v=Lt-YLuA0Qqg
, but unfortunately my screen-capturing rate was highly distorted by drawing the normals so the frame rate shoots up when I disable them. It is hard to see the choppiness, but it is there.
I should clarify again that the frame rate has never been the problem; it feels very sluggish to respond to the peripherals.