cannot edit the text entry box when open the window at first time

[Hz <hozenshi gmail com>]

http://www.pygtk.org/pygtk2tutorial/sec-TextEntries.html#entryfig

This link is the pygtk's official example. While running on my WIN7 system,
the text entry box cannot be edited since the first time opening. But if
you move mouse to activate other window, and turn back to this gtk window,
the text entry box can be edited then. I am not sure if this is a pygtk's
bug.

I also meet this kind of issue in my own application and have posted a
question on stackoverflow.com but no one response, so I came to here
looking for help. Here is stackoverflow link:
http://stackoverflow.com/questions/14038104/cannot-access-text-entry-box-after-reopen-the-gtk-window


I have tried python 2.6.6 and 2.7.3 with pygtk2.24.2-all-in-one.