Has anyone experienced this graphical glitch when typing in Firefox address bar?
The drop-down list is not drawn correctly, with some "blocks" missing. After typing more letters or hovering the mouse cursor, the list redraws itself and becomes complete.

I'm running Ubuntu 12.04, Firefox 13.0.1 and this only happens in KDE (tested with 4.8.2, 4.8.3 and 4.8.4). It does not happen in Unity or Xfce with the same user profile.

If I go to the KDE control panel and disable the Fade effect, the bug starts to happen to almost every menu in the system, including, the taskbar window previews. Enabling the “Fade” effect corrects the bug everywhere except in Firefox.

I have an Nvidia card and I am using the proprietary driver (current, not current-updates -- not sure about the difference), but the linked question on an Arch Linux forum says this happen with the open source driver and with other cards too.

Does anyone have an idea for a solution?