Comment 1 for bug 362359

When this occurs, it would appear that the point at which mouse events occur is also locked, though I have a very difficult time confirming. Specifically, when the focus is locked on the xfce4-panel system tray applet, context-menu-click (default right-click) brings the context menu associated with just one system tray item, regardless of where the pointer points. Additionally, hovering the cursor over different areas of the screen will still only display tooltips for one specific item, and not necessarily one that is being hovered over.

This occurs for me in both Xfce4 and Gnome. I've only observed this bug while more than one window is open. However, this is a fairly common state, and closing windows does not remove the effects.

Similar to above listed curious effects, I've noticed a couple things will "dislodge" the stuck focus (temporarily):
•Sometimes Alt-Right-click seems to allow focus travel normally until the next time I click on a control, at which point focus is stuck again.
• Switching workspaces using hotkey usually works, but is still temporary, and focus promptly becomes stuck once I click again.