setting size problem

[Omar Armas Aleman <kaos jlagunez iquimica unam mx>]

I have a frame, and within the frame a set of icons and lists, but the
widgets inside the frame all set it's size to the biggest widget.
Here is the code:

frame = gtk_frame_new ("Opciones");
  gtk_box_pack_start (GTK_BOX(main_vb), frame, TRUE, TRUE, 0);



  bbox = gtk_hbutton_box_new ();
  gtk_container_border_width (GTK_CONTAINER (bbox), 5);
  gtk_container_add (GTK_CONTAINER (frame), bbox);
  // gtk_button_box_set_layout (GTK_BUTTON_BOX (bbox),
GTK_BUTTONBOX_SPREAD);
  //  gtk_button_box_set_spacing (GTK_BUTTON_BOX (bbox), 20);
  //  gtk_button_box_set_child_size (GTK_BUTTON_BOX (bbox), 85, 20);


  search_frame = gtk_frame_new ("Buscar");
  gtk_box_pack_start (GTK_BOX(bbox), search_frame, TRUE, TRUE, 0);

  search_box = gtk_hbox_new (TRUE, 0);
  gtk_container_add (GTK_CONTAINER(search_frame), search_box);

  /*--- Search Options Button---*/
  omenu = gtk_option_menu_new ();
  gtk_box_pack_start (GTK_BOX(search_box), omenu, TRUE, TRUE, 0);
  menu = gtk_menu_new ();
  fill_omenu(menu);
  gtk_option_menu_set_menu (GTK_OPTION_MENU(omenu), menu);


  button_search = gtk_button_new_with_label(_("Buscar"));
  gtk_box_pack_start (GTK_BOX(search_box), button_search, TRUE, TRUE, 0);
  gtk_signal_connect (GTK_OBJECT (button_search), "clicked",
                      GTK_SIGNAL_FUNC (do_search), NULL);  


how do i solve it?
is the problem in the box or buttons settings?

Omar