Go to the URL and search for something common on the page (like "CSS 3"), after a few occurrences have been found, the content in the main column will shift left so that the edge is obscured. It only seems to happen when the found selection is below what is displayed in the window.
This happens because the overflow scrolls automatically to reveal the found text.
Created attachment 11358 [details]
I cannot reproduce the bug any more on TOT!
I can't reproduce it either - closing!