Hello.

Model:

public sealed class Model
{
    public string Value { get; set; }
}

Controller:

[HandleError]
public class HomeController : Controller
{
    [HttpGet]
    public ActionResult Index()
    {
        return View(new Model { Value = "+" } );
    }

    [HttpPost]
    public ActionResult Index(Model model)
    {
        model.Value += "1";
        return View(model);
    }
}

View:

<%using (Html.BeginForm()){%>
  <%: Model.Value %>
  <%: Html.HiddenFor(model => model.Value) %>
  <input type="submit" value="ok"/>
<%}%>

Every time I submitted form result is

<form action="/" method="post">+1
<input id="Value" name="Value" type="hidden" value="+">
<input type="submit" value="ok">
</form>

It means that HiddenFor helper doesn't use real value of Model.Value but uses passed to controller one. Is it bug in MVC framework? Does anyone know workaround?