Switching accelerators

["Andrew E. Makeev" <andrew solvo ru>]

Good day,

I am using window with notebook that has few pages.
Each page contains complex toolbar + widgets and GtkTreeView with
ListStore as model.
Toolbar has REFRESH button that allows user to update data from DB.
"F5" accelerator is connected to that toolbutton.

Glib::RefPtr< Gtk::ActionGroup > m_refMainGrod;
Gtk::Toolbar toolbar;

{
...

    Glib::RefPtr<Gtk::Action> action = Gtk::Action::create
	( "refresh", Gtk::Stock::REFRESH, "", instanceProperties.m_refresh );

    m_refMainGroup->add
	( action,
	  Gtk::AccelKey( "F5",
			 Glib::ustring( "<Actions>/MainGroup/" ) + toolbar.get_name() + "/refresh" ),
	  sigc::bind( sigc::mem_fun( *this,
				     &GridToolbar::actions_handler ),
		      REFRESH ) );

    Gtk::ToolItem* item = action->create_tool_item();
    item->set_tooltip( *instanceProperties.tooltips, instanceProperties.m_refresh );
    item->set_expand( false );
    item->set_homogeneous( false );
    toolbar.append( *item );
/*
Here I am trying to change active accelerator when notebook page is
switched. So, connecting to map/unmap signals.
*/
    item->signal_map().connect
	( sigc::bind( sigc::mem_fun( *this, &GridToolbar::connect_accelerators ), action ) );
    item->signal_unmap().connect
	( sigc::bind( sigc::mem_fun( *this, &GridToolbar::disconnect_accelerators ), action ) );
...
}

void GridToolbar::connect_accelerators( Glib::RefPtr< Gtk::Action > action )
{
    action->set_accel_group( grid_->m_Form->getWindow()->get_accel_group() );
    action->connect_accelerator();
}

void GridToolbar::disconnect_accelerators( Glib::RefPtr< Gtk::Action > action )
{
    action->disconnect_accelerator();
}

All works well until I pack toolbar into ScrolledWindow, and I have no
option to avoid that, unfortunatelly.
I should use gtk_scrolled_window_add_with_viewport(), because my widget
doesn't support scrolling innate, and that causes to drop GTK_NO_WINDOW
flag (GtkViewport does that).
When I was following signals I discovered that widget with GTK_NO_WINDOW
send SIGNAL_UNMAP for all children, but if that flag unset widget just
called gdk_window_hide(), and all underlaying childred has not received
SIGNAL_UNMAP.

Is it bug or some documented "feature"?

versions: Gtk+-2.4.13, Gtkmm-2.4.11 on Linux AS4-64

1. Is there a RIGHT way to switch accelerators, different from using
signal_map/signal_unmap?
2. Or should I just connect my handler to signal_unmap on widget that
yet receives the signal?

Thanks in advance,
-andrew

P.S.
Sorry, for english.
If someone would help but couldn't understood me well, let me know,
please.