Alerts getting security trimmed for LDAP users

Hi all,

I'm trying to get alerts working for our extranet users, which are stored in AD LDS.  Alerts work fine when I add a user explicitly to a List's ACL instead of using the LDAP group (role) the user is a member of.  I've narrowed it down to the fact that the Timer service is not aware of the role provider I've set up, as per this article:

http://msdn.microsoft.com/en-us/library/bb977430.aspx

Thus the timer service thinks the user doesn't have access to the list, and should not receive an alert for the list - i.e. security trimming.

The article is for the SQL role provider though, not LDAP, so I think my syntax is wrong somewhere.  This is what I configured:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<configuration>
  <system.web>
    <membership defaultProvider="ADAMMembership">
      <providers>
        <add name="ADAMMembership"
       type="Microsoft.Office.Server.Security.LDAPMembershipProvider, Microsoft.Office.Server, Version=12.0.0.0, Culture=neutral, PublicKeyToken=71E9BCE111E9429C"
        server="mysrv01"
        port="50000"
        useSSL="false"
        userDNAttribute="distinguishedName"
        userNameAttribute="cn"
        userContainer="CN=Users,CN=SharePoint,DC=mydomain,DC=local"
        userObjectClass="user" 
        userFilter="(ObjectClass=user)" 
        scope="Subtree" 
        otherRequiredUserAttributes="sn,givenname,cn" />
      </providers>
    </membership>
    <roleManager defaultProvider="LdapRole" enabled="true" cacheRolesInCookie="true" cookieName=".PeopleDCRole">
      <providers>
        <add name="LdapRole"
        type="Microsoft.Office.Server.Security.LDAPRoleProvider, Microsoft.Office.Server, Version=12.0.0.0, Culture=neutral, PublicKeyToken=71E9BCE111E9429C"
        server="mysrv01"
        port="50000"
        useSSL="false"
        groupContainer="CN=Users,CN=SharePoint,DC=mydomain,DC=local"
        groupNameAttribute="cn"
        groupMemberAttribute="member"
        userNameAttribute="cn"
        dnAttribute="distinguishedName"
        groupFilter="(ObjectClass=group)"
        scope="Subtree"/>
      </providers>
    </roleManager>
    <authentication mode="Forms">
      <forms loginUrl="/_layouts/login.aspx" />
    </authentication>
    <identity impersonate="true" />
    <globalization fileEncoding="utf-8" />
  </system.web>
</configuration>

I've restarted the timer service after adding the file to the \bin folder.  Any ideas?

thanks

Ray