distutils not finding all of my pure python modules

[Jeremy]

I have a small set of Python packages/modules that I am putting
together.  I'm having trouble in that when I run

python setup.py sdist

I don't get all of my pure python modules.  The setup.py script I use
is:

# =====================================
from distutils.core import setup

purePythonModules = ['regex', 'gnuFile']

setup(name='PythonForSafeguards',
    version='0.9.1',
    description = 'Python code for MCNP and Safeguards analysis.',
    author = 'Jake the Snake',
    author_email = 'something at blah.com',
    packages = ['MCNP', 'Safeguards'],
    url='http://lanl.gov',
    py_modules = purePythonModules,
    )

# =========================================

Everythin seems to work fine except the gnuFile.py script does not get
put into the distribution.  I know the file exists in the same
directory as regex.py and has the same permissions.

Does anyone know what is going on here?  I'm using Python 2.6.4.

Thanks,
Jeremy