MVC :: RedirectToAction Failing To Match Default Route In MVC3

I have a Search Controller with an action method as follows:

public ActionResult Location(LocationSearchInputModel input)
{
// Get Results and pass cacheId in TempData
return RedirectToAction("results");
}
public ActionResult Results()
{
// Get cacheId from TempData and build Model
return View(model);
}

The call to RedirectToAction fails with the following error message:

Message: No route in the route table matches the supplied values.

My default Route is set up as follows:

routes.MapRoute(null, "{controller}.mvc/{action}/{id}/", new { controller = "Home", action = "Index", id = UrlParameter.Optional });

As the id Parameter in the default Route is optional shouldn't RedirectToAction("results") execute the SearchController's Results action?

It worked in MVC2 :/