Here are a couple articles that explain how to make registry changes via Group Policy (GPO). This was used to get Screen Savers to work correctly when the regular user needed permissions to a registry key.
Here is how you set registry permissions via GPO:
http://channels.lockergnome.com/windows/archives/20050111_set_registry_permissions_using_group_policy.phtml
This is the change you need to make for the Logoff Screen Saver to work:
http://support.microsoft.com/default.aspx?scid=kb;en-us;156677
AND IT WORKS!!!
