Roles Not Working for Web.Sitemap

I have the following section in Web.Config


<siteMap defaultProvider="XmlSiteMapProvider" enabled="true">

      <providers>
        <add name="XmlSiteMapProvider"
          description="Default SiteMap provider."
          type="System.Web.XmlSiteMapProvider "
          siteMapFile="Web.sitemap"
          securityTrimmingEnabled="true" />

      </providers>
    </siteMap>

and i have following Node in Web.Sitemap


 <siteMapNode url="~/mp/appadm/agencymgr/agencyinfo/Default.aspx" title="Agency Information"  description="Create/List/Update Agency Information" >
          <siteMapNode url="~/mp/appadm/agencymgr/agencyinfo/createagency.aspx" title="New Agency"  description="Create a New Agency" roles="Student"/>
          <siteMapNode url="~/mp/appadm/agencymgr/agencyinfo/listagency.aspx" title="List Agency "  description="List Agency" />
          <siteMapNode url="~/mp/appadm/agencymgr/agencyinfo/editagency.aspx" title="Edit Agency"  description="Update Agency Information" />
         </siteMapNode>

I have specified that One Node (first from above 3) is for Role “Student”

what as i am testing it with username with “Administrator” Role, it shouldn’t show that Node, but its still there.

What am i doing wrong?

and, can i specify multiple roles for one Node?? i assume i can do it iwth comma seperated list.

Please Help

try adding a clear:

<providers>
    <clear />
    <add name="XmlSiteMapProvider"
      description="Default SiteMap provider."
      type="System.Web.XmlSiteMapProvider "
      siteMapFile="Web.sitemap"
      securityTrimmingEnabled="true" />
</providers>

After I add clear it is working perfect, thank you ben. In the first person the mistake was at the root sitemap not we need to add roles=“*”, then it will work perfectly.