Binding to Odata using PointDataSource

[MattMiley]

I'm trying to bind graphics to an Odata Service. The listbox and details grid work, but I can't get the graphics to show on the map

<UserControl
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    xmlns:esri="http://schemas.esri.com/arcgis/client/2009" x:Class="SilverlightClient.MainPage"
    mc:Ignorable="d"
    d:DesignHeight="300" d:DesignWidth="400">

    <Grid x:Name="LayoutRoot" Background="White">
        <Grid.Resources>
            <esri:SimpleMarkerSymbol x:Key="SelectMarkerSymbol" Size="12" Color="Red" />
        </Grid.Resources>
        
        <Grid.RowDefinitions>
            <RowDefinition />
            <RowDefinition />
            <RowDefinition />
        </Grid.RowDefinitions>
        
        <ListBox ItemsSource="{Binding}" DisplayMemberPath="ID" x:Name="PointsList" Margin="8" />
        <StackPanel DataContext="{Binding SelectedItem, ElementName=PointsList}" Margin="8" Grid.Row="1">
            <TextBlock Text="Details:"/>
            <TextBlock Text="{Binding ID}"/>
            <TextBlock Text="{Binding Lat}"/>
            <TextBlock Text="{Binding Lon}"/>
            <TextBlock Text="{Binding Desc}"/>
        </StackPanel>
        <esri:Map Background="White" Grid.Row="2"  WrapAround="True">
            <esri:ArcGISTiledMapServiceLayer Url="http://services.arcgisonline.com/ArcGIS/rest/services/World_Street_Map/MapServer"/>
            <esri:GraphicsLayer>
                <esri:GraphicsLayer.GraphicsSource>
                    <esri:PointDataSource
                            ItemsSource="{Binding}"
                            XCoordinateBinding="{Binding Lat}"
                            YCoordinateBinding="{Binding Lon}">
                    </esri:PointDataSource>
                </esri:GraphicsLayer.GraphicsSource>
                <esri:GraphicsLayer.Renderer>
                    <esri:SimpleRenderer Symbol="{StaticResource SelectMarkerSymbol}" />
                </esri:GraphicsLayer.Renderer>
            </esri:GraphicsLayer>
        </esri:Map>
    </Grid>
</UserControl>

using SilverlightClient.ServiceReference;
using System;
using System.Collections.Generic;
using System.Data.Services.Client;
using System.Linq;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;

namespace SilverlightClient
{
    public partial class MainPage : UserControl
    {
        public MainPage()
        {
            InitializeComponent();
            this.Loaded += new RoutedEventHandler(MainPage_Loaded);
        }

        void MainPage_Loaded(object sender, RoutedEventArgs e)
        {
            var ctx = new SpatialEntities(new Uri("/DemoNonSpatial.svc", UriKind.Relative));
            var qry = from g in ctx.SpatialDemoTable
                      select g;

            var coll = new DataServiceCollection<SpatialDemoTable>();
            coll.LoadCompleted += new EventHandler<LoadCompletedEventArgs>(coll_LoadCompleted);
            coll.LoadAsync(qry);

            DataContext = coll;
        }

        void coll_LoadCompleted(object sender, LoadCompletedEventArgs e)
        {
            if (e.Error != null)
            {
                MessageBox.Show("Error Detected, handle accordingly.");
            }
        }
    }
}

Am I missing something??