Is it a bug with gdk_property_get() ,implemented in directFB?

[sandy_21 <sandy_21 sina com>]

   Hi :

    I invoked this API like this:
       
       int    actual_length,actual_format;
       GdkAtom  actual_property_type;
       jobject *obj_ptr;

        gdk_property_get (event->any.window,
                gdk_atom_intern ("_GNU_GTKAWT_ADDR", FALSE),
                gdk_atom_intern ("CARDINAL", FALSE),
                0,
                sizeof (jobject),
                FALSE,
                &actual_property_type,
                &actual_format,
                &actual_length/*NULL*/,
                (guchar **)&obj_ptr))

 the output like following:

 (:9559): Gdk-DirectFB-CRITICAL **: file gdkwindow-directfb.c: line 1702
(gdk_window_get_events): assertion `GDK_IS_WINDOW (window)' failed

 (:9559): Gdk-DirectFB-CRITICAL **: file gdkwindow-directfb.c: line 1714
(gdk_window_set_events): assertion `GDK_IS_WINDOW (window)' failed

 (:9559): Gdk-DirectFB-CRITICAL **: file gdkproperty-directfb.c: line 225 
(gdk_property_change): assertion `GDK_IS_WINDOW (window)' failed

         every time this error will happen,is  it a bug of gdk_property_get 
in DirectFB,when i build gdk-target=linux-fb,then compile the app,same error
 ocur.Somebody can help me?thanx