stuff in the <system.WebServer section only works when using an Integrated app pool, I don't think it will work in a Classic app pool and it probably will not work in versions of IIS lower than 7. other configuration issues may also affect it.
I just tested this on my local machine:
<location path="test.htm">
<system.webServer>
<httpRedirect enabled="true" destination="http://demo.mojoportal.com/blog.aspx" httpResponseStatus="Permanent" />
</system.webServer>
</location>
and when I tried localhost/test.htm it did redirect me