gtk not working

Hi,
   I'm having a bit of troulbe getting pylab.show() to display a figure drawn with matplotlib.

The Test:

python
import pylab
pylab.plot([0,0],[1,1])
pylab.show()

I do not recieve an error, though I also do not see the graph.

FC4 x86_64 install

python-matplotlib-debuginfo-0.87.7-2
python-matplotlib-0.87.7-2

gtk2-2.6.10-2.fc4.4.i386
gtk2-2.6.10-2.fc4.4.x86_64
gtk2-devel-2.6.10-2.fc4.4.i386
gtk2-devel-2.6.10-2.fc4.4.x86_64

When I build the rpms from the srpm I see the following, though the build continues.

pygtk present but import failed

In /usr/src/redhat/BUILD/matplotlib-0.87.7/examples I run

'python subplot_demo.py -dGTKAgg'

and get

'ImportError: No module named _ns_backend_gdk'

Am I missing something?

Thanks!
Adam Miller