Using sp_change_users_login ‘auto_fix’ to fix user/login
http://rainstorms.me.uk/blog/2010/02/21/using-sp_change_users_login-auto_fix-to-fix-userlogin/-- Shared with Google Share Button
When moving a database between sql servers, the login information for the server is not included in the move. This results in databases that have users defined but no associated logins, making them orphans.
This article details a stored procedure to fix the issue, "sp_change_users_login 'auto_fix', 'username'"