AttributeError: 'FlatManager' object has no attribute 'allocate_network'

hi, I followed the below link for installing Nova in Ubuntu 10.10

http://wiki.openstack.org/NovaInstall/MultipleServer

while i try to run Step no 4

 /usr/bin/python /usr/bin/nova-manage project create <project_name> <user_name>

Iam getting the following error

INFO:root:backend <module 'nova.db.sqlalchemy.api' from '/usr/lib/pymodules/python2.6/nova/db/sqlalchemy/api.pyc'>
/usr/lib/pymodules/python2.6/nova/db/sqlalchemy/api.py:42: DeprecationWarning: Use of empty request context is deprecated
  DeprecationWarning)
Traceback (most recent call last):
  File "/usr/bin/nova-manage", line 457, in <module>
    main()
  File "/usr/bin/nova-manage", line 449, in main
    fn(*argv)
  File "/usr/bin/nova-manage", line 297, in create
    self.manager.create_project(name, project_manager, description)
  File "/usr/lib/pymodules/python2.6/nova/auth/manager.py", line 488, in create_project
    self.network_manager.allocate_network(context,
AttributeError: 'FlatManager' object has no attribute 'allocate_network'
root@cncc:~# /usr/bin/python /usr/bin/nova-manage project create asdshadjsavdfsahdfhsafdfjsadafs ss
INFO:root:backend <module 'nova.db.sqlalchemy.api' from '/usr/lib/pymodules/python2.6/nova/db/sqlalchemy/api.pyc'>
/usr/lib/pymodules/python2.6/nova/db/sqlalchemy/api.py:42: DeprecationWarning: Use of empty request context is deprecated
  DeprecationWarning)
Traceback (most recent call last):
  File "/usr/bin/nova-manage", line 457, in <module>
    main()
  File "/usr/bin/nova-manage", line 449, in main
    fn(*argv)
  File "/usr/bin/nova-manage", line 297, in create
    self.manager.create_project(name, project_manager, description)
  File "/usr/lib/pymodules/python2.6/nova/auth/manager.py", line 484, in create_project
    member_users)
  File "/usr/lib/pymodules/python2.6/nova/auth/dbdriver.py", line 101, in create_project
    manager = db.user_get({}, manager_uid)
  File "/usr/lib/pymodules/python2.6/nova/db/api.py", line 575, in user_get
    return IMPL.user_get(context, id)
  File "/usr/lib/pymodules/python2.6/nova/db/sqlalchemy/api.py", line 92, in wrapper
    return f(*args, **kwargs)
  File "/usr/lib/pymodules/python2.6/nova/db/sqlalchemy/api.py", line 1296, in user_get
    raise exception.NotFound('No user for id %s' % id)
nova.exception.NotFound: No user for id ss
root@cncc:~# /usr/bin/python /usr/bin/nova-manage project create asdshadjsavdfsahdfhsafdfjsadafs cn
INFO:root:backend <module 'nova.db.sqlalchemy.api' from '/usr/lib/pymodules/python2.6/nova/db/sqlalchemy/api.pyc'>
/usr/lib/pymodules/python2.6/nova/db/sqlalchemy/api.py:42: DeprecationWarning: Use of empty request context is deprecated
  DeprecationWarning)
Traceback (most recent call last):
  File "/usr/bin/nova-manage", line 457, in <module>
    main()
  File "/usr/bin/nova-manage", line 449, in main
    fn(*argv)
  File "/usr/bin/nova-manage", line 297, in create
    self.manager.create_project(name, project_manager, description)
  File "/usr/lib/pymodules/python2.6/nova/auth/manager.py", line 488, in create_project
    self.network_manager.allocate_network(context,
AttributeError: 'FlatManager' object has no attribute 'allocate_network'