Detached database file permissions
You should enable trace flag 1802 on your database servers.  This will allow SQL Server to retain inheritable permissions when you detach a database so you won't experience this issue going forward:

http://support2.microsoft.com/kb/922804

DBCC TRACEON(1802, -1)

Add it to the startup parameters of the SQL Server service
http://msdn.microsoft.com/en-us/library/ms190737(v=sql.110).aspx