Using custom images in Gtk::Action

[SMART_n <the smart n gmail com>]

Hello.
Is it possible to use a custom image as the icon in Gtk::Action? I have 
tried this way:

  Glib::RefPtr<Action> someAction = Action::create("SomeAction", 
"Caption");
  someAction->create_icon(IconSize())->set("<path to the image>");

But when I use this action with UIManager, the icon doesn't show. Is 
there any other ways?