ItemsPanelTemplate Differences in SL and WPF

I was changing the ItemsPanelTemplate of Listbox and set the Position of Elements generated using TranslateTransform

WPF app works fine, while the Silverlight app crashes. As far as I can tell the code is same

Here is the XAML
<UserControl x:Class=”t14.Page”
    xmlns=”http://schemas.microsoft.com/winfx/2006/xaml/presentation“
    xmlns:x=”http://schemas.microsoft.com/winfx/2006/xaml“
    Width=”400″ Height=”300″>
    <UserControl.Resources>
        <DataTemplate x:Key=”dt”>
            <TextBlock Text=”{Binding Name}”>
                <TextBlock.RenderTransform>
                    <TranslateTransform X=”{Binding Position.X}”
                                        Y=”{Binding Position.Y}” />
                </TextBlock.RenderTransform>
            </TextBlock>
        </DataTemplate>
    </UserControl.Resources>
    <Canvas x:Name=”c1″>
        <ListBox x:Name=”list1″ ItemTemplate=”{StaticResource dt}” >
            <ListBox.ItemsPanel>
                <ItemsPanelTemplate>
                    <Canvas Width=”500″ Background=”Azure”
                            Height=”500″></Canvas>
                </ItemsPanelTemplate>
            </ListBox.ItemsPanel>
        </ListBox>
    </Canvas>
</UserControl>

and code behind

public partial class Page : UserControl
    {
        public Page()
        {
            InitializeComponent();
            List<Customer> customers = new List<Customer>();
            customers.Add(new Customer { Name = “Customer..1″, Position = new Point {X=100,Y=100 } });
            customers.Add(new Customer { Name = “Customer..2″, Position = new Point { X = 50, Y = 50 } });
            customers.Add(new Customer { Name = “Customer..3″, Position = new Point { X = 150, Y = 150 } });
            customers.Add(new Customer { Name = “Customer..4″, Position = new Point { X = 200, Y = 200 } });
            list1.ItemsSource = customers;
        }

      
    }

    public class Customer
    {
        public Point Position { get; set; }
        public string Name { get; set; }
    }

I also tried to set ItemContainerStyle like this in SL, but it crashes

  <Style x:Key=”st1″
               TargetType=”ListBoxItem”>
            <Setter Property=”Canvas.Left”
                    Value=”{Binding Position.X}” />
            <Setter Property=”Canvas.Top”
                    Value=”{Binding Position.X}” />
        </Style>

I set same thing in WPF, it works

 <Style x:Key=”st1″ TargetType=”{x:Type ListBoxItem}”>
            <Setter Property=”Canvas.Left”
                    Value=”{Binding Position.X}” />
            <Setter Property=”Canvas.Top”
                    Value=”{Binding Position.X}” />
        </Style>
you can download the sample app here