Well then you can let Rick give a try as he suggested. But you will need to open a support ticket with access info.
I just suggested this fix since it works on some windows servers.
If the value is available. So it appears in your case it is not.
Memory reminds me the issue with iis is the script mapping value.
If you enable it it opens the site to security issues.
But it was dependent on what versions you were running. IIS5 or IIS6 or IISx.
