When a menu item is created with gtk_image_menu_item_new_with_label() or gtk_image_menu_item_new_with_mnemonic(), it will start life with a ref_count of 2.

This means that it will not be destroyed when removed from the container it is added to using gtk_container_remove(). (I realize that you can use gtk_widget_destroy() instead of gtk_container_remove() and it will make sure that the the menu item is removed and destroyed.)

The problem appears to be that gtk_accel_label_set_accel_widget() is called in the gtk_image_menu_item_new...() methods, which adds an additional ref_count.  Perhaps the menu item should simply be unreffed after the gtk_accel_label_set_accel_widget() call?