Gtk::Menu label not showing up after the first time displaying menu

["Jim Barnes" <j r barnes larc nasa gov>]

Hi all,

I've having problems with Gtk::Menus and popup-menus not displaying their
labels.  The first time that the menu is displayed, all menu labels are
displayed properly. On subsequent displays of the menu, the popup window for
the menu is displayed, but the window is missing the menu item labels.  When
the mouse goes over the popup window, the labels show up one by one.  Even
the separator lines are missing.

Here is a code snippet from my class.  Any help would be appreciated.

Thanks
Jim

HangarDialog::HangarDialog()
  : Gtk::Window(),
....
{
  // Set the window parameters.
  set_title("Hangar");
  set_resizable(true);

  const int border_width = 10;
  set_border_width(border_width);

  // Initialize the list of dialogs to add models to the simulation.
  add_model_dialogs[MODEL]          = 0;
  add_model_dialogs[STATIC_MODEL]   = 0;
  add_model_dialogs[PLAYBACK_MODEL] = 0;

  const int spacing = 5; // Spacing for formatting boxes.

  // Create the vertical packing box into which all objects will be placed.
  main_box = new Gtk::VBox(false, spacing);
  assume(main_box);
  main_box->show();
  add(*main_box);

  // Create the model_list that will be needed for the menu
  model_list = new PositionalModelList;

  // Create the Menu interface
  // Create a reference action group
  ref_action_group = Gtk::ActionGroup::create();

  // Define the actions
  ref_action_group->add(Gtk::Action::create("SimMenu", "_Simulation"));
  ref_action_group->add(
    Gtk::Action::create("SimControl",
                        "Sim Control",
                        "Modify simulation configuration."),
    sigc::mem_fun(this, &HangarDialog::showSimControlDialog));
  ref_action_group->add(
    Gtk::Action::create("SimEnvironment",
                        "Environment",
                        "Modify the simulation environment."),
    sigc::mem_fun(this, &HangarDialog::showEnvironmentDialog));

  ref_action_group->add(
    Gtk::Action::create("SimClose",
                        "Close Hanger", "Close this dialog."),
    sigc::mem_fun(this, hide));

(bunch more menus.....)

  ref_action_group->add(Gtk::Action::create("HelpMenu", Gtk::Stock::HELP,
"Help"));

  // Create a ui_manager
  ui_manager = Gtk::UIManager::create();

  // Insert the the ActionGroup
  ui_manager->insert_action_group(ref_action_group);

  // Layout the actions in a menubar
  try
  {
    Glib::ustring ui_info =
      "<ui>"
      "  <menubar name='Menubar'>"
      "    <menu action='SimMenu'>"
      "      <menuitem action='SimControl'/>"
      "      <menuitem action='SimEnvironment'/>"
      "      <separator/>"
      "      <menuitem action='SimClose'/>"
      "    </menu>"
      "    <menu action='ModelsMenu'>"
      "      <menu action='ModelsAddMenu'>"
      "        <menuitem action='AddModel'/>"
      "        <menuitem action='AddPlayback'/>"
      "        <menuitem action='AddStatic'/>"
      "        </menu>"
      "      <menuitem action='ModelsDelete'/>"
      "    </menu>"
      "    <menu action='HardwareMenu'>"
      "      <menuitem action='HardwareDrivers'/>"
      "      <menuitem action='HardwareInterfaces'/>"
      "      <menuitem action='HardwareChangeSelected'/>"
      "    </menu>"
      "    <menu action='HelpMenu'>"
      "    </menu>"
      "  </menubar>"
      "</ui>";

    ui_manager->add_ui_from_string(ui_info);
  }
  catch ( const Glib::Error& ex)
  {
    string error = "Buiding Menu Bar faild: " + ex.what();
    TerminalIO::applicationError("PlotMenuBarFactory::PlotMenuBarFactory()",
                                 error.c_str(), false, true);
  }

  // Add the menubar to the vbox
  Gtk::Widget* menu_bar = ui_manager->get_widget("/Menubar");

  if (menu_bar)
  {
    main_box->pack_start(*menu_bar, Gtk::PACK_SHRINK);
  }

...

  show_all_children();

  // Every 10 ms update the components of this dialog.
  const int update_period_in_milliseconds = 10;
  Glib::signal_timeout().
    connect(sigc::mem_fun(this, &HangarDialog::updateComponents),
            update_period_in_milliseconds);
}