Beta 2: Image not appearing at runtime (set using Blend)

 Hello,
I have an Image in my XAML that was added in Blend and appears with the following markup:
<Image Height="Auto" HorizontalAlignment="Center" Margin="247,77,263,87"
                VerticalAlignment="Stretch" Width="Auto"
                Source="Spinner.jpg" Stretch="None" />
The image appears correct inside the Blend designer, however, when I run the app, no image appears.
Does anyone have any ideas what might be causing this?  I've tried using JPG instead of PNG with the same results..

Best regards,
- Sean  
 
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