menu not displaying any data

[Growls]

Am I missing something here? menu is not displaying any data, even though adding a breakpoint on the query and look at the results it is returning 3 records.
adminMenu user control:

<%@ Control Language="C#" AutoEventWireup="true" CodeBehind="adminMenu.ascx.cs" Inherits="Waivenet.adminMenu" %>
<%@ Register Assembly="Telerik.Web.UI" Namespace="Telerik.Web.UI" TagPrefix="telerik" %>
<telerik:RadMenu ID="RadMenu1" runat="server">
</telerik:RadMenu>

adminMenu code behind:

using System;
using System.Collections.Generic;
using System.Linq;
using Waivenet.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace Waivenet
{
    public partial class adminMenu : System.Web.UI.UserControl
    {


        protected void Page_Load(object sender, EventArgs e)
        {
DataClassesDataContext dbcontext = new DataClassesDataContext();
            RadMenu1.Skin = SessionWrapper.skin;
            var sdf = from s in dbcontext.siteMaps.ByHierarchy<siteMap>(t => t.sitemapID == SessionWrapper.siteMapIDCurrent, (parent, child) => (parent.sitemapID == child.parentID)) select new { s.Item.parentID, s.Item.sitemapID, s.Item.name, s.Item.pagePath };
            RadMenu1.DataFieldID = "sitemapID";
            RadMenu1.DataFieldParentID = "parentID";
            RadMenu1.DataTextField = "name";
            RadMenu1.DataValueField = "sitemapID";
            RadMenu1.DataNavigateUrlField = "pagePath";
            RadMenu1.DataSource = sdf;

            RadMenu1.DataBind();

        }
    }
}

If I use an <items> tag in the markup the menu displays it no probs. the ByHierarchy extension method is a way to retrieve hierarchal linq data, stolen from here: http://weblogs.asp.net/okloeten/archive/2006/07/09/Hierarchical-Linq-Queries.aspx

[Growls]

If I remove the hierarchal data fields:
 RadMenu1.DataFieldID = "sitemapID";            
 RadMenu1.DataFieldParentID = "parentID";
then the three records display one after the other without any hierarchal relationship.
as soon as I add them the control doesnt render.
Is this a new bug introduced? (I downloaded the latest version of rad controls and am using it, RadControls_for_ASP.NET_AJAX_2009_3_1208_dev

[Yana]

Hi Growls,

Please check whether you've set null to parentID of the root items.

Best regards,
Yana
the Telerik team

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[Growls]

that fixed it thanks! Sorry for my moronism.