[Zope] SimpleUserFolder setup problem

[Sreekanth S Rameshaiah]

Dear All,
Greetings !!!
I just now downloaded SimpleUserFolder ind installed in my Zope
instance.
Installation was sucessful.

As per the installation instruction, I have created all the required 
ZSql methods.( i.e, addUser, deleteUser, editUser,getUserDetails,
getUserNames ) in the controlpanel-> products -> Simpleuserfolder

The necessary tables have been created in the database and all the
querys have been tested to ensure that querys are syntactically correct.



But whenever i try to create a user in acl_users folder which is
SimpleuserFolder instance i get the following error.

  File /usr/local/Zope-2.4.4-src/lib/python/AccessControl/User.py, line
871, in manage_users
    (Object: acl_users)
  File /usr/local/Zope-2.4.4-src/lib/python/AccessControl/User.py, line
802, in _addUser
    (Object: acl_users)
  File
/usr/local/zope/lib/python/Products/SimpleUserFolder/SimpleUserFolder.py, line 86, in _doAddUser
    (Object: acl_users)
UnconfiguredException: Addition of users has not been configured


Has anybody come across this error message?
Is there any way around this?
Thanks
  -  sree