gannotate does not save the pane position

While investigating warnings that appear when the test runner is run I discovered this
    /usr/lib/python2.7/dist-packages/gi/types.py:43: Warning:
      g_value_get_object: assertion `G_VALUE_HOLDS_OBJECT (value)' failed
      return info.invoke(*args, **kwargs)
happens when GAnnotateConfig tried to connect a callback to the pane's 'handle' event.

http://developer.gnome.org/pygobject/stable/class-gobject.html reports that
"A TypeError exception is raised if detailed_signal identifies a signal name that is not associated with the object".

I confirmed that the pane's position is not saved and restored.