Proposed fix - Missing file in support for support for nspkg.pth-style namespaces?

Following htgoebel's commit 2cf7654e35 and his comment on ticket #502 at http://www.pyinstaller.org/ticket/502

My test case on Mac OS X 10.6.6, Python 2.7.6:
$ pip list
...
PyInstaller (2.1.1dev-7dd9dce)
Twisted (14.0.0)
zope.interface (4.1.1)

$ pyinstaller script.py
...  File ".../lib/python2.7/site-packages/PyInstaller/build.py", line 139, in compile_pycos
    open(fnm, 'rb').read()[:4] != imp.get_magic())
IOError: [Errno 2] No such file or directory: '.../lib/python2.7/site-packages/PyInstaller/fake/namespace/__init__.pyc'

$ pip list
...
PyInstaller (2.1.1dev-95da1bb)
Twisted (14.0.0)
zope.interface (4.1.1)

$ pyinstaller script.py
Packages and runs successfuly

IMPORTANT:
* I did not study the underlying code.
* Maybe this is the wrong approach at fixing this.
* Thanks in advance for any input.