ASP.NET MVC Beta Authorize attribute sends me to wrong action

Today I started playing with the MVC 3 Beta. Started with an application from default MVC 3 template, added a new action in the Home controller as follows(with a view for it)

[Authorize]
public ActionResult Secured()
{
    ViewModel.Message = "This is secured area, only authenticated users should be here.";
    return View();
}

Now when I try to go to navigate to Secured action I get a 404 page not found error.

Here is the authentication section from my web.config.

<authentication mode="Forms">
  <forms loginUrl="~/Account/LogOn" timeout="2880" />
</authentication>

If I understood it right the Authorize attribute should result in a 401 unauthorized HTTP response which should be intercepted by the authentication handler and redirect me to the loginUrl. Which should result in Account/LogOn action.

My MVC 2 application works as expected and takes me to Account/LogOn action, am I missing something? or Is this a bug in MVC 3 beta?