matplotlib window icon

Hello,

I'm developing a plugin in pygtk, which indirectly (via networkx) uses
matplotlib to display graphs.

Now, I have the following problem: When I import pylab, my window icon
(the small icon in the window decoration) gets replaced by the
matplotlib icon. I pasted a sample script below to illustrate.

This is amazingly annoying for me since I am merely writing a plugin for
an existing application and cannot simply replace the original window
icon.

Is there any way to supress this behaviour?

Please help me, and thanks in advance,
Fred

# ------------------------------------- sample code below
#!/usr/bin/python

import gtk
import pylab

w = gtk.Window()
b = gtk.Button("click me")
w.add(b)
w.show_all()

gtk.main()