title: ContentEditable iframe is not editable in firefox
body: <p>I am having an issue with contentEditable iframes in Firefox. I created an iframe for pasting rich text and it worked excellently in Chrome. However, for some reason the iframe is not editable in Firefox and IE. When I load the iframe in FF, the cursor blinks in the iframe and then disappears, never to return. Here is the HTML as it loads in Chrome:</p>
  
  <pre><code>&lt;iframe id="atto_pastespecial_iframe" frameborder="0" style="border: 1px solid gray"&gt;
  #document
       &lt;html&gt;
           &lt;head&gt;&lt;/head&gt;
           &lt;body contenteditable="true"&gt;&lt;/body&gt;
       &lt;/html&gt;
  &lt;/iframe&gt;
  </code></pre>
  
  <p>However, here is how it looks in FF:</p>
  
  <pre><code>&lt;iframe id="atto_pastespecial_iframe" frameborder="0" style="border: 1px solid gray"&gt;
  #document
       &lt;html&gt;
           &lt;head&gt;&lt;/head&gt;
           &lt;body&gt;&lt;/body&gt;
       &lt;/html&gt;
  &lt;/iframe&gt;
  </code></pre>
  
  <p>I am adding the HTML via YUI Javascript: (Edit to show how the iframe is added)</p>
  
  <pre><code>_addIframe: function(container) { //Container points at div to insert iframe into
      container.setHTML('&lt;iframe id="atto_pastespecial_iframe" src="javascript: window.onload(document.getElementByTagName(\'body\').contentEditable=\'true\')" frameBorder="0" style="border: 1px solid gray"&gt;&lt;/iframe&gt;');
      var ifr = Y.one('#atto_pastespecial_iframe');
      var doc = ifr.get('contentWindow.document');
  
      // Set the iframe to be editable by the user
      doc.one('body').setAttribute('contentEditable', 'true');
      doc.one('body').focus();
  </code></pre>
  
  <p>Does anyone know why the iframe is editable in Chrome, but not FF or IE?</p>