When I run my Silverlight app, this code doesn't play a video at all:
    <MediaElement
        Source="winvideo-201DataGridPreview.wmv"
        AutoPlay="True"
        AudioStreamIndex="2"
        Margin="10"
        Height="200"
        Width="200"/>
From all of the examples I can find of MediaElement, it seems to be the correct syntax, etc.
Is there anything I'm forgetting?