I created a scroll bar and got an animation bug in WebKit.
I tested these browsers:
ff 3.0.17, 3.6 Windows XP, Ubuntu 10.04
Opera 9.64, 10.10, 10.61, Windows XP
Chromium 7.0.503.0 (57022) Ubuntu 10.04 BUG
Google Chrome 5.0.375.127 Windows XP BUG
Apple Safari 4.0.4 (531.21.10) Windows XP BUG
Such horizontal scrollbar is on the SONY site http://www.sony.ru/hub/vaio
Bug occurs when you zoom the page and CLICK on the left or the right of the slider and you will see that the animation does not begin with the current slider position.
I can attach my files with my scrollbar, which has the same bug when you zoom the page.
Perhaps this is not your bug, but WebKit. Frankly, I doubt it.
Fix it please. Or write to me and I'll resend the bug to webkit.org
Sorry for my poor english. I was used the google translator