The current version of xfce4-panel (4.12.0) in Ubuntu 16.04 is suffering from a nasty repainting error: https://bugs.launchpad.net/ubuntu/+source/xfce4-panel/+bug/1397095 A fix was released almost a year ago: https://git.xfce.org/xfce/xfce4-panel/commit/?id=8dc83f507d7340fa46c5b8927e5b320c5595fb7d Any chance for an update? Thanks!