title: Error 800706B5 when calling IWebBrowser2->get_Document
body: <p>On Vista using IE8, I have an instance of IWebBrowser2, which I am using to obtain the current HTML document:</p>
  
  <pre><code>IWebBrowser2* browser;
  CComPtr&lt;IDispatch&gt; disp;
  HRESULT hr = browser-&gt;get_Document(&amp;disp);
  </code></pre>
  
  <p>When this is executed by an Administrator, the call succeeds. However, when called by a regular user, the call returns an error code of "800706B5" ("The interface is unknown") despite the page being on a "Trusted Site" and "Protected Mode" being off.</p>
  
  <p>This same code worked without problems on IE7 on Vista, and with IE8 on XP. </p>
  
  <p>Does anyone know why this error might be occurring, and what I can do to resolve the issue? Running as administrator is less than ideal, and Jon Skeet is stumped by this one too :)</p>
  
  <p>Update: the question seems to revolve around UAC: turning off UAC completely allows things to work for a regular user (though it's distinctly unsafe)</p>