Users are being logged into the server as unknown
I have set up users and groups in workgroup manager and assigned permissions to share points in server admin on a Mac OS X 10.6.8 server. Users are logged into the server with their account ID and password, which should limit their access to the permissions assigned to them or their group, but every user who logs into the server is being logged in as "unknown" with read & write privileges.
MacBook Pro, Mac OS X (10.7.3)