Help with Glade-3 and gtk.ScrolledWindow

[asomers gmail com]

I'm trying to use a Scrolled Window in my application, but without
success.  Using a TextView as the child widget works, but for any
other child widget I get the following error when I run the program:

scrolled-win.py:17: GtkWarning: gtk_scrolled_window_add(): cannot add
non scrollable widget use gtk_scrolled_window_add_with_viewport()
instead
  builder.add_from_file('scrolled-win.xml')

Then the program appears but without any scroll bars.

I've attached a test case.  My system is:
Ubuntu 9.04 amd64
python 2.6.2
python-gtk2-dev 2.14.1-1ubuntu
glade-3 3.6.3

Does anybody know what I'm doing wrong?  Here is what I've tried already:
1) Using a table of buttons, or a table of labels, or an image as the
child widget of the ScrolledWindow produces the same results
2) Using a TextView as the child widget produces the desired result
3) Using libglade instead of gtk.Builder produces the same results
4) Saving the project in libglade format, then converting it with
gtk-builder-convert and loading it with gtk.Builder produces the same
results
5) Running the example at
http://www.micahcarrick.com/12-24-2007/gtk-glade-tutorial-part-1.html
produces the same results, if I replace its TextView widget with a
table of buttons.
6) Running the C example at that same website produces the same results.
7) Running the scrolledwin.py example from python-gtk2-tutorial works.
 This example does not use Glade in any way.

-Alan Somers