Updating value provider prior to TryUpdateModel

Answer 1

The real issue behind the scenes here is that Html.HiddenFor wasn't displaying the correct value even though TryUpdateModel was updating a value in the model to give to the view.

The issue here is that the Html helpers assume if you are rendering a view after a post, there mustve been an error (otherwise you wouldve redirected back to the view with a GET method - hence the Post Redirect Get issue)

This is described in detail at: http://blogs.msdn.com/b/simonince/archive/2010/05/05/asp-net-mvc-s-html-helpers-render-the-wrong-value.aspx