Guest Management Permissions Error

Hi, We have a Fortigate 110C with FortiOS 5.0.1. I have been trying to setup a Guest Wireless Network with the Captive portal enabled. I created a Wireless Guest group and a admin account restricted to Provision Guest Accounts associated with this Group. When I logon as this restricted user to the Fortigate and try to create a account, I can fill in all the information, but as soon as I click ok I get ' Permission Denied. Insufficient Privileges. I can delete accounts created by the Super_Admin account, but I' m not sure where to grant this permission. The documentation doesn' t state there is anything else to it. Any help would be very much appreciated.