Internet Explorer may not detect a content type change from text/html to text/xml or from text/html to application/pdf

If the ContentType property of a URL changes but the URL stays the same, Internet Explorer displays the new contents of the page with the old content type. To see the information displayed correctly with the new content type, you must open a new instance of Internet Explorer.

This problem occurs if the ContentType property changes in one of the following ways:

• From "text/html" to "text/xml"
• From "text/xml" to "text/html"
• From �text/html� to �application/pdf�

Note The default for Active Server Pages (ASP) is "text/html."

Microsoft has confirmed that this is a bug in the Microsoft products that are listed at the beginning of this article.

Steps to reproduce the behavior

Note These steps assume that you are familiar with Internet Information Server (IIS) and Active Server Pages (ASP).

1. Create a new ASP page with the following code:

   <%@ Language="VBScript" Codepage="65001" %>
   
   <% 	Response.ContentType = "text/xml" %>
   
   <XMLSTUFF>
   This is some stuff
   </XMLSTUFF>
   					

2. Save this ASP file as ContentType.asp to the default Web site of your IIS server.
3. Start a new instance of Internet Explorer, and browse to the newly created ASP page (for example, http://<Your_IIS_Server>/ContentType.asp). Notice that the content appears as XML.
4. Do not close the browser window, and open the ASP page. Comment out the ContentType line as follows:

   'Response.ContentType = "text/xml"'
   						

   and save the ASP page again.
5. Refresh the browser window. Notice that the content still appears as XML, even though the content type has changed.
6. Open a new instance of Internet Explorer, and browse to the ASP page. Notice that the content appears with the ASP default content type of "text/html."