Hope this help:
*For sqlserver 2005 you can run this (this might work, i havnt tested yet). This is used when you do restore by copying the mdf file. I dont know why these codes do not work in sqlserver 2008
Use sde
Exec sp_change_users_login 'update_one', 'sde', 'sde'
Exec sp_change_users_login 'update_one', 'username', 'pwd'
Use yourdb
Exec sp_change_users_login 'update_one', 'sde', 'sde'
Exec sp_change_users_login 'update_one', 'username', 'pwd'
*For sqlserver 2008 you can run this. This works when you restore database from backup file :
use sde
go
EXEC sp_change_users_login 'Auto_Fix', 'sde',NULL, 'pwd'
go
use yourdb
go
EXEC sp_change_users_login 'Auto_Fix', 'user',NULL, 'pwd'
go
use yourdb
go
EXEC sp_change_users_login 'Auto_Fix', 'sde',NULL, 'sde'
go
use sde
go
EXEC sp_change_users_login 'Auto_Fix', 'user',NULL, 'sde'
go