--- a/demo_checkbox.py	Wed Jan 02 11:48:36 2013 +0100
+++ b/demo_checkbox.py	Fri Jan 04 00:13:59 2013 +0100
@@ -10,7 +10,7 @@
 class MyApplication(Application):
     def __init__(self):
         Application.__init__(self)
-        self.top.connect('keypress', self.on_top_keypress)
+        self.top.add_handler('keypress', self.on_top_keypress)
 
         self.top.layout = VerticalLayout(homogeneous=False)