Restful routning bug

rrbug.cs

  //This is the route definition
  public class Routes : RouteSet{
    public Routes() {
      Map("").To<HomeController>(x => x.Index());
      Area<HomeController>("", () =>
        Map("").To<HomeController>(x => x.Index()));
      Map("rss").To<FeedController>(x => x.Rss());
      Map("atom").To<FeedController>(x => x.Atom());
      Resources<PostController>(
        () => {
          Member("id", HttpVerbs.Get);
          Member("delete", HttpVerbs.Get);
        });
      Resources<TagController>(() => Only("show"));
      Resource<LoginController>(() => {
                                  Only("show");
                                  Member("authenticate", HttpVerbs.Post);
                                  Member("signout", HttpVerbs.Get);
                                });
      Resources<UserController>();
      Resource<BlogMLController>(() => {
                                   Only("show");
                                   Member("import", HttpVerbs.Post);
                                 });
    }
  }

  //This is a failing unit test:
    [Test]
    public void login_is_mapped_to_login_controller() {
      "~/login".Route().ShouldMapTo<LoginController>(x => x.Show());
      "~/login/signout".Route().ShouldMapTo<LoginController>(x => x.SignOut());
      //This assertion fails, the rest pass
      "~login/authenticate".Route().ShouldMapTo<LoginController>(x => x.Authenticate(null));
    }

  //This is the controller
	public class LoginController : Controller{
		readonly IUserTasks _userTasks;

		public LoginController(IUserTasks userTasks) { _userTasks = userTasks; }

		public ActionResult Show() {
			if (_userTasks.IsLoggedIn()) return RedirectToAction("Index", "Home");
			return View(new LoginViewModel());
		}

		[HttpPost, ValidateAntiForgeryToken, Transaction]
		public ActionResult Authenticate(LoginViewModel model) {
			_userTasks.AuthenticateUser(model.Username, model.Password);
			return RedirectToAction("Index", "Home", new {area = "Admin"});
		}

		public ActionResult SignOut() {
			_userTasks.SignOut();
			return this.RedirectToAction<HomeController>(x => x.Index());
		}
	}

//This is the view
<%@ Page Language="C#" MasterPageFile="~/Views/Shared/Site.Master" AutoEventWireup="true" Inherits="ModelViewPage<Graphite.Web.Controllers.Login.LoginViewModel>" %>
<%@ Import Namespace="Graphite.Web.Controllers.Login" %>

<asp:Content ContentPlaceHolderID="main" runat="server" >
<%
  using (Html.BeginForm<LoginController>(x => x.Create(Model))) {%>
  <div class="formInput"> 
	   <%= this.TextBox(x => x.Username).Label("Username: ")%>
  </div>
  <div class="formInput">
	  <%= this.Password(x => x.Password).Label("Password: ")%>
  </div>
  <%=Html.AntiForgeryToken()%>
  <%=this.SubmitButton("Login")%>
<%
  }%>
</asp:Content>