PRB: document.readyState Not in Sync with Download in IFrame

MORE INFORMATION

Steps to Reproduce Behavior

Here is HTML code that reproduces the problem. When you press the button, an IFrame is inserted before the end of the body. Then, a message box is displayed to show the value of document.readyState. At this point, document.readyState is set to complete. The readyState should change as the document in the IFrame is downloaded.

<HTML>
<HEAD>
   <TITLE>IFrame/readyState Bug</TITLE>

   <SCRIPT LANGUAGE="VBScript">
   Sub btn_onClick
      document.body.insertAdjacentHTML "BeforeEnd", _
         "<IFRAME SRC='http://www.microsoft.com'></IFRAME>"

      MsgBox "ReadyState: " + document.readyState
   End Sub
  </SCRIPT>
</HEAD>
<BODY>
   <BUTTON ID="btn">Insert IFrame</BUTTON>
</BODY>
</HTML>