title: Event triggers don't work
body: <p>I have some trigger in my Windows Phone 7 Silverlight app such as </p>
  
  <pre><code>&lt;Grid x:Name="ContentGrid" Grid.Row="1" Background="Red" Height="100"&gt;
      &lt;Grid.Triggers&gt;
          &lt;EventTrigger RoutedEvent="Loaded"&gt;
              &lt;BeginStoryboard&gt;
                  &lt;Storyboard&gt;
                      &lt;DoubleAnimationUsingKeyFrames BeginTime="00:00:00" Storyboard.TargetProperty="Opacity"&gt;
                          &lt;SplineDoubleKeyFrame KeyTime="00:00:00" Value="0"/&gt;
                          &lt;SplineDoubleKeyFrame KeyTime="00:00:10" Value="1"/&gt;
                      &lt;/DoubleAnimationUsingKeyFrames&gt;
                  &lt;/Storyboard&gt;
              &lt;/BeginStoryboard&gt;
          &lt;/EventTrigger&gt;
      &lt;/Grid.Triggers&gt;
  &lt;/Grid&gt;
  </code></pre>
  
  <p>But when Loaded event fires, XamlParseException occurs.
  I googled a bit, but found nothing.</p>
  
  <p>Any idea to find solution? 
  Thanks.</p>