Window decoration does not handle mouse events after restoring from maximize or fullscreen to window

[Paulos]

After maximizing a window (or going to fullscreen) and then going back to window, the window decoration (title, buttons, border) becomes unresponsive to any mouse events. The window itself still accepts mouse hover and clicks, but the decoration around does not register any mouse events and passes any clicks / hovers to the underlying window.

However, the decoration still updates based on whether the window has focus or not. Hiding the window (eg. by minimizing) and restoring fixes the problem momentarily - until next maximize.

Steps to reproduce:

1) Start any application.
2) Maximize it or put it to fullscreen.
3) Restore the window.
4) Observe that the decoration does not register mouse events.
5) Minimize and restore the window to restore functionality.

Ubuntu version: 13.04 Raring alpha