One of our least-favorite tasks is moving a database.  This is a well-documented pain for a simple reason: user logins.  Each SQL server has a unique id (SID) attached to each user so even if the user name is the same, the login may-or-may-not be linked to the DB permissions. This article has a better description and a great solution:

http://www.sqlservercentral.com/articles/Log+Shipping/63028/