problems with mmtk

[Glenn Johnson]

I have just started trying to learn mmtk. I am getting the following when I 
start:

Python 1.5.1 (#2, Jul  9 1998, 13:54:11)  [GCC 2.7.2.1] on freebsd3
Copyright 1991-1995 Stichting Mathematisch Centrum, Amsterdam
>>> from mmtk import *
Traceback (innermost last):
  File "<stdin>", line 1, in ?
  File "/usr/local/lib/python1.5/mmtk1.1b1/mmtk.py", line 38, in ?
    from Minimization import ConjugateGradientMinimizer, 
SteepestDescentMinimizer
  File "/usr/local/lib/python1.5/mmtk1.1b1/Minimization.py", line 8, in ?
    from _minimization import conjugateGradient, steepestDescent
ImportError: No module named _minimization
>>> 


Does any one have any idea what might be wrong. I have the following 
environment variables set in my '.cshrc':

setenv PTUI /usr/local/lib/python1.5/ptui-1.1b3
setenv MMTKPATH /usr/local/lib/python1.5/mmtk1.1b1
setenv PYTHONPATH /usr/local/lib/python1.5/ptui-1.1b3:/usr/local/lib/python1.5/
m
mtk1.1b1
setenv PDBVIEWER vmd

Thanks for your help in advance.
-- 
Glenn Johnson
Technician
USDA, ARS, SRRC
New Orleans, LA