I'm using the latest Firefox on windows 7 and don't seem to have a problem with it.
Mind you it's a desktop and I'm using a mouse not a touch-pad to scroll.
The slight choppiness i see is because of how scroll works not the website's fault.
When you scroll there's a minimum increment that gets detected and the equivalent on the website for that is quite large.
But reducing that would make you scroll a lot more and would probably be annoying.
If you want the smoothness of a magic mouse use the down arrow on the scroll bar or your keyboard.
The slight choppiness i see is because of how scroll works not the website's fault.
When you scroll there's a minimum increment that gets detected and the equivalent on the website for that is quite large. But reducing that would make you scroll a lot more and would probably be annoying.
If you want the smoothness of a magic mouse use the down arrow on the scroll bar or your keyboard.