[gtkmm] Dynamic page addition to Gtk::Notebook problem

[Alexandros Frantzis <alf82 freemail gr>]

Hello,
I have a problem adding pages to a Gtk::Notebook. For example to 
dynamically add pages to the notebook example program from the tutorial 
I added a New button. The code below is called whenever the button but 
nothing seems to happen to the notebook.

void ExampleWindow::on_button_new()
{
    Gtk::Label *l=Gtk::manage(new Gtk::Label("New Label"));
    m_Notebook.append_page(*l,"New");
    std::cout<<"New Button Pressed"<<std::endl;
}

Any hints?

Thanks in advance,
Alexandros Frantzis