I've found that this bug is actually triggered by upgrade of libgtk2.0-0, not xfce4-panel. Version 2.21.0-1ubuntu2 is affected, and version 2.20.1-0ubuntu1 isn't.
** Summary changed: - [Maverick] System tray became unusable after upgrade to xfce4-panel 4.6.4-1 + [Maverick] XFCE system tray became unusable after upgrade to libgtk2.0-0 2.21.0-1ubuntu2 ** Description changed: - Binary package hint: xfce4-panel - - After upgrade to xfce4-panel 4.6.4-1, system tray stopped working. No - icons are visible, and CPU load is 100% while tray is displayed (task - manager attributes most of this load to X server). + After upgrade to libgtk2.0-0 2.21.0-1ubuntu2, XFCE system tray stopped + working. No icons are visible, and CPU load is 100% while tray is + displayed (task manager attributes most of this load to X server). + Workaround is to downgrade libgtk2.0-0 to version 2.20.1-0ubuntu1. Architecture: amd64 Linux 2.6.34-3-generic xserver-xorg 1:7.5+5ubuntu1 xserver-xorg-video-intel 2:2.9.1-3ubuntu5 libxfce4util4 4.6.2-1ubuntu1 libxfcegui4-4 4.6.4-1 libexo-0.3-0 0.3.107-1ubuntu1 xfce4-panel 4.6.4-1 ** Also affects: gtk+2.0 (Ubuntu) Importance: Undecided Status: New -- [Maverick] XFCE system tray became unusable after upgrade to libgtk2.0-0 2.21.0-1ubuntu2 https://bugs.launchpad.net/bugs/586012 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs