wpf maskedTextBox Databindings - wpf

Question

I am using the following MaskedTextBox http://wpftoolkit.codeplex.com/wikipage?title=MaskedTextBox in a person project for my own use. This is a simple example because i am trying to use this on a much bigger program but I am using this program to test this control.
STEPS:
1. Create a wpf application
2. Added a Linq to SQL Class called Prescriptions and added a table called info
{ID | Name | Phone}
The markup for the form is listed below:
<Window x:Class="MaskedTest.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:xctk="http://schemas.xceed.com/wpf/xaml/toolkit"
Title="MainWindow" Height="300" Width="300"
Loaded="Window_Loaded">
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
<RowDefinition Height="Auto"/>
<RowDefinition Height="Auto"/>
<RowDefinition Height="*" />
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto"/>
<ColumnDefinition Width="200"/>
</Grid.ColumnDefinitions>
<Label Name="nameLabel" Margin="2" Target="{Binding ElementName=nameTxt}">_Full Name</Label>
<TextBox Name="nameTxt" Grid.Column="1" Margin="2" Text="{Binding Name}"/>
<Label Name="phoneLabel" Margin="2" Grid.Row="1" Grid.Column="0" Target="{Binding ElementName=phoneTxt}">_Phone Numnber</Label>
<xctk:MaskedTextBox Name="phoneTxt" Margin="2" Grid.Row="1" Grid.Column="1" Text="{Binding Phone}" Mask="[phone]" />
</Grid>
Code Behind File:
public partial class MainWindow : Window
{
private PrescriptionDataContext pdc = new PrescriptionDataContext();
private List<info> users = new List<info>();
private info U = new info { Id = 1, Name = "Matthew Brown", Phone = "5128289081" };
public MainWindow()
{
InitializeComponent();
}
private void Window_Loaded(object sender, RoutedEventArgs e)
{
var q = pdc.getUser();
foreach (info I in q)
{
users.Add(I);
}
// DOES NOT WORK
this.DataContext = users;
// WORKS
// this.DataContext = U;
}
}
When this loads, you will see that the name field has been binded correctly but the phone control shows only the mask not the underlying data from the table. If I explicity create the class and then bind it like i did above it works.
Ideas??