Comment 11 for bug 877318

Fabrice: Instead you can do...

                if os.name == "posix" :
                    icon_theme = gtk.icon_theme_get_default()
                    pixbuf = icon_theme.load_icon ('stock_person', 50, gtk.ICON_LOOKUP_USE_BUILTIN)
                elif os.name == "nt" :
                    pixbuf = None