Database users are stored in the sysusers table. Their permissions are stored in the syspermissions table. Both of these tables are part of the database catalog that is within every database. When you do a database backup, this information is also backed up.

My belief was that you are seeing a common problem when people restore a database to another server. All database users are mapped from a Login. If you restore a database to a server that does not have the logins from the original server, the SEM cannot display the login that the database user was mapped to. The users are still there. You'll see them if you query the sysusers table. The SID column in sysusers maps back to the SID column in master..sysxlogins. Think of it has an INNER JOIN filtering out rows that don't meet the join constraint.

The system stored procedure sp_change_users can assist with establishing a link between orphanned database users and logins. BTW, this system stored procedure exists only in SQL Server 7.0 and 2000.

Anyway, that was my guess to your problem. If this is not your problem then I not sure what the issue is.

-Mike