How To Unit Test ValueProviderFactories In MVC3

We wanted to upgrade our projects from ASP.NET MVC 2 to 3. Most of our tests succeeded, but there are some that fail on ValueProviderFactories.Factories.GetValueProvider(context).

Here is a simple test class that ilustrates the problem.

[TestFixture]
public class FailingTest
{
[Test]
public void Test()
{
var type = typeof(string);
// any controller
AuthenticationController c = new AuthenticationController();
var httpContext = new Mock<HttpContextBase>();
var context = c.ControllerContext = new ControllerContext(httpContext.Object, new RouteData(), c);

[Code]...