Python GTK3 on Windows not fully working?

Question

I started working through the PyGObject and GTK3 tutorials here...

http://python-gtk-3-tutorial.readthedocs.org/en/latest/introduction.html

and as soon as I got to the second example, Python would just hang up and not do anything. I've stripped away all the button references and it works so it appears to be something related to the buttons? Installation problem maybe?

• Windows Vista 64bit
• Python 3.4
• Newest GTK3 installed
• PyGObject installed via installer here

Edit:

Example Code

#!/usr/bin/python
from gi.repository import Gtk

class MyWindow(Gtk.Window):

    def __init__(self):
        Gtk.Window.__init__(self, title="Hello World")

        self.button = Gtk.Button(label="Click Here")
        self.button.connect("clicked", self.on_button_clicked)
        self.add(self.button)

    def on_button_clicked(self, widget):
        print("Hello World")

win = MyWindow()
win.connect("delete-event", Gtk.main_quit)
win.show_all()
Gtk.main()