So far, this seems to be limited to horizontal menus, but we are looking into the issue. If you haven't already, please subscribe to the newsletter for the latest updates.
// um.073=0. In chromium um.ss=true so this if block is entered. Whereas in safari
um.ss=false so the block is not entered. The block does some webkit unsupported style
operations which throw DOM exception in both chromium and safari.