keystone-manage: error: argument command: invalid choice: 'db' from postinst

Precise A2 updated at time of this bug.

Just done an install of OpenStack and Keystone now has changed to an interactive session (breaking all previous unattended installs) due to introduction of dbconfig. The install fails due to what looks like a syntax error creating entries in the database.

Replacing config file /etc/dbconfig-common/keystone.conf with new version
granting access to database keystone for keystone@localhost: success.
verifying access for keystone@localhost: success.
creating database keystone: success.
verifying database keystone exists: success.
dbconfig-common: flushing administrative password
usage: keystone-manage [-h]

                       {create_credential,create_endpoint_template,create_role,create_service,create_tenant,create_token,create_user,delete_credential,delete_endpoint_template,delete_role,delete_service,delete_tenant,delete_token,delete_user,downgrade_database,goto_database,grant_role,list_credentials,list_endpoint_templates,list_endpoints,list_roles,list_services,list_tenants,list_tokens,list_users,map_endpoint,revoke_role,sync_database,unmap_endpoint,update_credential,update_endpoint_template,update_role,update_service,update_tenant,update_token,update_user,upgrade_database,version,version_control_database}
                       ...
keystone-manage: error: argument command: invalid choice: 'db' (choose from 'create_credential', 'create_endpoint_template', 'create_role', 'create_service', 'create_tenant', 'create_token', 'create_user', 'delete_credential', 'delete_endpoint_template', 'delete_role', 'delete_service', 'delete_tenant', 'delete_token', 'delete_user', 'downgrade_database', 'goto_database', 'grant_role', 'list_credentials', 'list_endpoint_templates', 'list_endpoints', 'list_roles', 'list_services', 'list_tenants', 'list_tokens', 'list_users', 'map_endpoint', 'revoke_role', 'sync_database', 'unmap_endpoint', 'update_credential', 'update_endpoint_template', 'update_role', 'update_service', 'update_tenant', 'update_token', 'update_user', 'upgrade_database', 'version', 'version_control_database')
dpkg: error processing keystone (--configure):
 subprocess installed post-installation script returned error exit status 2
Errors were encountered while processing:
 keystone
E: Sub-process /usr/bin/dpkg returned an error code (1)
root@openstack2:/etc/dbconfig-common# dpkg -l | grep keystone
iF keystone 2012.1~e4~20120203.1574-0ubuntu2 Proposed OpenStack identity service - Daemons
ii python-keystone 2012.1~e4~20120203.1574-0ubuntu2 Proposed OpenStack identity service - Python library

Also:
1) Is this auto create necessary / can it be optional?
2) What does it create so I know what can be catered for with an unattended install?