title: Viewstate is null on postback
body: <p>Right, I've got something very peculiar going on here...</p>
  
  <p>ASP.NET 4 page with the following property:</p>
  
  <pre><code>protected QuickShopBag QuickShopBagInstance
  {
      get { return (QuickShopBag)ViewState["QuickShopBag"]; }
      set { ViewState["QuickShopBag"] = value; }
  }
  </code></pre>
  
  <p>During the initial <code>Page_Load()</code> in (<code>!Page.IsPostBack</code>) the <code>QuickShopBagInstance</code> is populated and <code>ViewState</code> saved.</p>
  
  <p>However when you perform a postback on the page the ViewState is empty when accessed from the postback <code>Button_OnClick()</code> event!!!</p>
  
  <p>I've checked the Request.Form and sure enough the <code>_Viewstate</code> value is there and is populated. I've also ran this value through a parser and it does contain the expected data, the page has <code>ViewStateEnabled="true"</code> and the new .NET 4 <code>ViewStateMode="Enabled"</code>.</p>
  
  <p>I've moved on to override the LoadViewState method to check to see if it is firing, it doesn't appear to be.</p>
  
  <pre><code>protected override void LoadViewState(object savedState)
  {
      base.LoadViewState(savedState);
  }
  </code></pre>
  
  <p>I am really lost as to what could possibly be the problem. Any ideas?</p>