Userjs, accelerating scrolling pages on Habré

I noticed that with the introduction of the x-sidebar on the Habré (this is such a thing with a refresher of the page and a counter of new comments to the bottom of the page), the scrolling of the page was not that slow down, but some discomfort appeared. The problem, of course, is that the sidebar is fixed and the browser has to redraw the entire page while scrolling, and not just the part that is invisible before. I did not want to give up the sidebar at all, so I wrote a small user-js, which makes the sidebar positioning absolute and sometimes puts it in its place. The positive effect is very noticeable in the Opera.

homm.stratero.ru/pages/user-js/habrascroll.js

I hope that you know how to put user-js in Opera and FF.