Protection For Secured Uploaded Files

Hi,

I need to deny access to all the uploaded files (.wmv, .doc etc.) from Anonymous users and I did everything this thread  mentions. The protection works. However, I am having problem with the authenticated users not able to view .wmv files. There is an error "The Source filter for this file could not be loaded" and the .wmv file can't be played.

I have security configuration setting set in the web.config to protect the entire folder from Anonymous users:

 <configuration>
      <location path="Client">
            <system.web>
                  <authorization>
   ...