Slider Issue - From B1 to B2

 

 I have an application I am converting from beta 1 to beta 2. I use a slider to provide a zoom control. In beta 1 the following simple code worked fine:
private void sldZoomLevel_ValueChanged(object sender, RoutedEventArgs e)
   {
      ZoomLevel = (int)sldZoomLevel.Value;
   }

In beta 2 during this method is being called during the app startu ...