title: Symfony 2.0 login does not work with Symfony 2.1?
body: <p>Is there something special I need to do, because I have three applications on Symfony 2.0 and after the login I can use any of those apps, but one Symfony 2.1 app does not work (does not authenticate) and it asks me to login. If I do that, Symfony 2.0 apps are logged out.</p>
  
  <p>Has the authentication system changed radically? How do I adapt?</p>