[gtkmm] Small icons on gtkmm

[Sergio Pascual Ramírez <spr astrax fis ucm es>]

Hello, Im trying to asign a small icon to my gtkmm application, of the 
style that appears in the gnome tasklist.

I have tried this (but it doesnt work):

In the ctor:

NS_main::NS_main(){
......
realize.connect(slot(this,&NS_main::set_icon_cb));
......
}

void NS_main::set_icon_cb(){
  this->get_window().set_icon_name("pixmap.xpm");
}

Im using gtkmm 1.2.9 and redhat's gcc "2.96"