A caveat when working with Windows domain users in your SQL Server is the possibility of orphaned users.  When a user is removed from AD, they are not automatically removed from SQL Server.  This is an orphaned user as far as SQL Server is concerned.  Thus, no access will be provided to this account even if the AD account is recreated because it will have a new SID that will not match the existing item stored in SQL Server.  You can run the sp_validatelogins stored procedure to display if any orphaned users are in the database.

To resolve this problem you will need to remove the user using DROP LOGIN ‘AD\Annie’.  Then you will need to revoke the user’s server access using EXEC sp_revokelogin ‘AD\Annie’ to remove the user’s access to the server.

Enjoy!