error loading ropemacs #8

I have a folder like this:

---------------------------
cb_utils/
   __init__.py
   ...
   ..several py files..
   ..several modules..
   math/
      __init__.py
      simplex.py
------------------------- 

I cannot load any file from cb_utils/ in emacs using python mode (with ropemacs/ropemode/autocomplete loaded in (eval-after-load "python-mode").

I get: "Pymacs loading ropemacs.....failed" and in Pymacs window:

<23 (version "0.24-beta2")
>45 eval pymacs_load_helper("ropemacs", "rope-")
<13 (return nil)

If I remove my math module I have no problem. Somehow this module (cb_utils.math) is giving naming problems with the python math module ???

(sorry for my english...)