From an webapplication on a 2003 webserver trying to access a sql server 2008r2 login in failed.
Verifiyed domain account is in the security. The account is a service using the application pool.
have reset the app pool and the username password still unable to connect.
Only upgrading the sql server from server2003r2 to Server 2008r2 and also upgraded from sql 2008 to sql 2008r2
Webserver nothing changed and the user account we are using can connect to the db using Management studio.