title: Knockoutjs multiselect not updated
body: <p>Updated code:</p>
  
  <p><a href="http://jsfiddle.net/S96pA/1/" rel="nofollow">http://jsfiddle.net/S96pA/1/</a></p>
  
  <pre><code>&lt;!DOCTYPE html&gt;
  &lt;html lang="en"&gt;
  &lt;head&gt;
  &lt;meta charset="utf-8"&gt;
  &lt;script src="http://ajax.googleapis.com/ajax/libs/jquery/1.8.0/jquery.min.js" type="text/javascript"&gt;&lt;/script&gt;
  &lt;script src="http://github.com/downloads/SteveSanderson/knockout/knockout-2.2.0.js" type="text/javascript"&gt;&lt;/script&gt;
  
  &lt;/head&gt;
  
  &lt;body&gt;
  
  &lt;form id="new-pub"&gt;
  
      &lt;input data-bind="value: Title" /&gt;&lt;br/&gt;
  
      &lt;select size="10" multiple="multiple"
              data-bind="selectedOptions: Attachment, options: AttachmentSelect"&gt;&lt;/select&gt;
  
  
  &lt;/form&gt;
  
  
  &lt;script type="text/javascript"&gt;
  
  var AttachmentSelect=["C2012_info_mail.pdf", "C2012_programme.pdf"];
  
   var viewModel =
   {
      Title : ko.observable('Hello world'),
      Attachment: ko.observableArray([ "C2012_info_mail.pdf" ,  "C2012_programme.pdf" ])
  };
  
   ko.applyBindings(viewModel, document.getElementById("new-pub"));
  
  &lt;/script&gt;
  
  &lt;/body&gt;
  &lt;/html&gt;
  ​
  </code></pre>
  
  <p>Expected, that <code>selected</code> items are highlighted (selected), but nothing happens. Why?</p>