problem with svn install

Hi all,
I have a problem with an svn install.
I've followed the instruciont on mpl website, that is:

$ svn co matplotlib
$ cd matplotlib
$ python develop

Please note that i've run the last command with sudo as i'm explicitly asked to do so.

Then if i run this simple test script:

from pylab import *

from the command line as

python --verbose-helpful

i get thise output:

davide@...2692...:~$ python --verbose-helpful
matplotlib data path /home/davide/partizione/matplotlib/lib/matplotlib/mpl-data
loaded rc file /home/davide/partizione/matplotlib/lib/matplotlib/mpl-data/matplotlibrc
matplotlib version 0.98.6svn
verbose.level helpful
interactive is False
units is False
platform is linux2
Traceback (most recent call last):
  File "mio", line 1, in <module>
    from pylab import *
  File "/home/davide/partizione/matplotlib/lib/", line 1, in <module>
    from matplotlib.pylab import *
  File "/home/davide/partizione/matplotlib/lib/matplotlib/", line 206, in <module>
    from matplotlib import mpl # pulls in most modules
  File "/home/davide/partizione/matplotlib/lib/matplotlib/", line 1, in <module>
    from matplotlib import artist
  File "/home/davide/partizione/matplotlib/lib/matplotlib/", line 5, in <module>
    from transforms import Bbox, IdentityTransform, TransformedBbox, TransformedPath
  File "/home/davide/partizione/matplotlib/lib/matplotlib/", line 34, in <module>
    from matplotlib._path import affine_transform
ImportError: /home/davide/partizione/matplotlib/lib/matplotlib/ failed to map segment from shared object: Operation not permitted

Could it be that i've installed in the wrong directory? If yes how can i cope with this?
Thanks in advance for any help.