Problem with matplotlib: "no module named _transforms"

Dear NG,

I have a problem mwith the installation of matplotlib under redhat 9 and python 2.3.2. I first updated all relevant packages (see [1]).
Building matplotlib with default setup.py seemd to be ok, except two types of warnings (see [2]). Install showed no errors as well.
When importing matplotlib I get the following error:
>>> from matplotlib import matlab
Traceback (most recent call last):
   File "<stdin>", line 1, in ?
   File "matplotlib/matlab.py", line 142, in ?
     from axes import Axes
   File "matplotlib/axes.py", line 9, in ?
     from artist import Artist
   File "matplotlib/artist.py", line 4, in ?
     from transforms import identity_transform
   File "matplotlib/transforms.py", line 180, in ?
     from _transforms import Value, Point, Bbox, Affine
ImportError: No module named _transforms

What could be the problem?
The directory /usr/lib/python2.3/site-packages/matplotlib/
contains transforms.py and _transforms.so but no _transforms.py - is that ok?

Thanks for any help,
    Mathias

···

--------
[1]: zlib, zlib-devel, libpng, libpng-devel, freetype, freetype-devel, freetype-utils, gtk2-devel, gtk+-devel, pygtk2, glib-devel, pygtk2-devel, gnome-libs-devel, pygtk2-libglade,
tcl, tk, tkinter

[2]: In file included from /usr/include/python2.3/Python.h:8,
                  from CXX/Objects.hxx:9,
                  from CXX/Extensions.hxx:18,
                  from src/_transforms.h:10,
                  from src/_transforms.cpp:2:
/usr/include/python2.3/pyconfig.h:847:1: warning: "_POSIX_C_SOURCE" redefined
In file included from /usr/include/c++/3.2.2/i386-redhat-linux/bits/os_defines.h:39,
                  from /usr/include/c++/3.2.2/i386-redhat-linux/bits/c++config.h:34,
                  from /usr/include/c++/3.2.2/functional:53,
                  from src/_transforms.cpp:1:
/usr/include/features.h:131:1: warning: this is the location of the previous definition