Adding -webkit-transform: translateZ(0) to the #sidebar fixed the issue for me. I've used translateZ(0) to fix numerous Chrome display bugs over the years. The rationale is that by invoking 3D transformation, re-paint is separated from the rest of the CSS pain stack (I can't provide much more detail than that, it's pretty much all Greek to me). In any case, it appears to work for me! #sidebar{ -we