[mod_python] pysid cookie timeout?

By running the Cookie manager on my browser I can see that the pysid
cookie times out when the browser terminates.

Is there a way to change the pysid timeout?  I do set the mod_python
session timeout but, since the pysid cookie is written when the session
is created (before I set the timeout), the mod_python session timeout
obviously has no effect on the pysid cookie timeout.

John