Model Builder wont start

[ss]

TOSHIBA Satellite M645-S4063 running Kubuntu 12.04 "Precise Pangolin" 64bit

ss@nn:~$ lsb_release -rd
Description: Ubuntu 12.04 LTS
Release: 12.04

ss@nn:~$ apt-cache policy model-builder
model-builder:
  Installed: 0.4.1-5
  Candidate: 0.4.1-5
  Version table:
 *** 0.4.1-5 0
        500 http://co.archive.ubuntu.com/ubuntu/ precise/universe amd64 Packages
        100 /var/lib/dpkg/status

Installation of model-builder and dependencies via apt
Starting PyMB in konsole results in the follwing output:

ss@nn:~$ PyMB
/usr/lib/pymodules/python2.7/matplotlib/__init__.py:923: UserWarning: This call to matplotlib.use() has no effect
because the the backend has already been chosen;
matplotlib.use() must be called *before* pylab, matplotlib.pyplot,
or matplotlib.backends is imported for the first time.

  if warn: warnings.warn(_use_error_msg)
Traceback (most recent call last):
  File "/usr/bin/PyMB", line 9, in <module>
    load_entry_point('Model-Builder==0.4.1', 'gui_scripts', 'PyMB')()
  File "/usr/lib/python2.7/dist-packages/pkg_resources.py", line 337, in load_entry_point
    return get_distribution(dist).load_entry_point(group, name)
  File "/usr/lib/python2.7/dist-packages/pkg_resources.py", line 2279, in load_entry_point
    return ep.load()
  File "/usr/lib/python2.7/dist-packages/pkg_resources.py", line 1989, in load
    entry = __import__(self.module_name, globals(),globals(), ['__name__'])
  File "/usr/lib/python2.7/dist-packages/model_builder/PyMB.py", line 32, in <module>
    import wxFrame1
  File "/usr/lib/python2.7/dist-packages/model_builder/wxFrame1.py", line 48, in <module>
    import wxFrame2, about
  File "/usr/lib/python2.7/dist-packages/model_builder/wxFrame2.py", line 33, in <module>
    import PlotFigure as PF
  File "/usr/lib/python2.7/dist-packages/model_builder/PlotFigure.py", line 25, in <module>
    import matplotlib.numerix as numpy
ImportError: No module named numerix

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: model-builder 0.4.1-5
ProcVersionSignature: Ubuntu 3.2.0-25.40-generic 3.2.18
Uname: Linux 3.2.0-25-generic x86_64
ApportVersion: 2.0.1-0ubuntu8
Architecture: amd64
Date: Thu Jun 21 20:29:31 2012
InstallationMedia: Kubuntu 12.04 LTS "Precise Pangolin" - Release amd64 (20120423)
PackageArchitecture: all
ProcEnviron:
 LANGUAGE=
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: model-builder
UpgradeStatus: No upgrade log present (probably fresh install)