[mod_python] Session Cookie Name

mod_python 3.1.4

Anyone been able to change the name of the session cookie?  According to
the Session.py module you should be able to do it in the apache config
file thus;

PythonOption session_cookie_name name_of_sid

Unfortunately it doesn't seem to take affect.  Am I doing anything
glaringly wrong?

P.S. this option does not appear to be documented anywhere.