title: Form submitted twice after updating from ASP MVC 3 Preview to Beta
body: <p>After upgrading my ASP MVC from 3 Preview to 3 Beta I see strange behaviour in my Ajax forms.</p>
  
  <pre><code>@using(Ajax.BeginForm("New", new AjaxOptions() {OnSuccess = "onAjaxSuccess", OnFailure = "onAjaxFailure", OnBegin = "onAjaxBegin", HttpMethod = "Post"})) {}
  
  &lt;form action="/Order/New" data-ajax="true" data-ajax-begin="onAjaxBegin" data-ajax-failure="onAjaxFailure" data-ajax-method="Post" data-ajax-success="onAjaxSuccess" method="post"&gt;&lt;/form&gt;
  </code></pre>
  
  <p>I have placed an <code>alert</code> inside my function <code>onAjaxBegin</code> and it is beeing fired twice, each time i click on my submit button.</p>
  
  <p>Anyone else seen this behaviour? I have not changed anything in the code after upgrading, and it worked perfectly before the upgrade.</p>