title: Newtonsoft json serializer returns empty object
body: <p>Ok - I've been beating my head against this for a few of hours now. Time to ask for help.</p>
  
  <p>I have just upgraded my Web application project to ASP.NET MVC 4 RC, and the new WebApi.
  My web api method is now returning EMPTY json "{}" - even though my object is fully populated.</p>
  
  <p>I have replace the serializer with my own MediaTypeFormatter that also calls the Newtonsoft Json serializer, just so I can hook in and see things working.
  What I see is an object going in to the serializer, and coming out as "{}".</p>
  
  <p>This USED to work before I upgraded.</p>
  
  <p>This is my object</p>
  
  <pre><code>[Serializable]
  public class Parameters
  {
      public string ApplicantName { get; set; }
  }
  </code></pre>
  
  <p>And I am just calling:</p>
  
  <pre><code>var result = JsonConvert.SerializeObject(new Parameters(){ Name = "test" });
  </code></pre>
  
  <p>I get back</p>
  
  <pre><code>"{}"
  </code></pre>
  
  <p>Whats going on??</p>
  
  <p>[EDIT]</p>
  
  <p>Someone else having the same problem... after running through the Newtonsoft source code, I can see we're having the exact same problem from a recent change.</p>
  
  <p><a href="http://json.codeplex.com/discussions/357850" rel="noreferrer">http://json.codeplex.com/discussions/357850</a></p>