Blocking access to non-aspx files and folders in web.config

 I am currently trying to block access to a folder containing .htm files, when i add a location tag with path="SuperFrame.aspx" it works perfectly. But when i set the path to "HtmlFiles/Bestellingen_6.htm" it does not work. It worked before, and the only thing i added is the membership/rolemanager authentication. piece of code from my web.config pasted below:
<roleManager enabled="true" />
<authentication mode="Forms">
      <forms loginUrl="EnduserLogin.aspx">
      </forms>
    </authentication>
<location path="HtmlFiles/Bestellingen_6.htm">
    <system.web>
    <authorization>
      <deny users="?"/>
<allow users="Default Group"/> ...