GtkOverlay problem after reparent in to GtkOffscreenWindow

[Denis Linvinus <linvinus gmail com>]

Hi, all!
I'm use GtkOffscreenWindow as tmp container, while animating window.
This is my object hierarchy:

GtkWindow
----------------GtkVBox - main container
-----------------------------GtkOverlay
--------------------------------------------GtkNotebook as main object in GtkOverlay
-------------------------------------------------------------VteTerminal
--------------------------------------------GtkButton as overlay object
-----------------------------GtkHbox
...

GtkOffscreenWindow

After reparent GtkVBox in to GtkOffscreenWindow, all widgets working well (GtkNoteBook/Vte too), except overlay object, button don't drawn after reparent,
even if reparent back to GtkWindow,
until call

this.main_overlay.hide();
this.main_overlay.unrealize();
this.main_overlay.show();

after that button drawing again.

This is my video with this problem http://www.youtube.com/watch?v=DIZd7pdIszI

I don't know is it GtkOffscreenWindow problem, or GtkOverlay (but think that it is GtkOverlay problem)
If i just show/hide GtkWindow, then button drawing without problems.

My system:
Ubuntu 11.10 amd64
libgtk-3-0     3.2.0-0ubuntu3
valac-0.14   0.14.0-0ubuntu1