This only eats 17% of my CPU on Windows7/Chrome but the animation still jerks. If I go to page 2 (navigation on top) it scrolls smoothly at first but starts jer

This only eats 17% of my CPU on Windows7/Chrome but the animation still jerks. If I go to page 2 (navigation on top) it scrolls smoothly at first but starts jerking later on. If I reload (page 2) it works fine again. What is going on here? Edit: It works smoothly with Firefox 3.6.6