Thank you for reporting this. I was able to reproduce with the following SDK sample: http://resourcesbeta.arcgis.com/en/help/silverlight-api/samples/start.htm#GenerateRendererI simply added these lines:XAML <Button Content="Prints" Click="Button_Click" Width="140" Height="30"
VerticalAlignment="Top" HorizontalAlignment="Left" Margin="5"/>
Code-Behind
private void Button_Click(object sender, RoutedEventArgs e)
{
var printTask = new PrintTask("http://yourservername:6080/arcgis/rest/services/Utilities/PrintingTools/GPServer/Export%20Web%20Map%20Task");
printTask.ExecuteCompleted+=new EventHandler<PrintEventArgs>(printTask_ExecuteCompleted);
printTask.ExecuteAsync(new PrintParameters(MyMap));
}
We will try to get this fixed before final.Meanwhile, if you replace the layer in XAML with the following code. It should work: <esri:ArcGISDynamicMapServiceLayer ID="USA"
Url="http://servicesbeta2.esri.com/arcgis/rest/services/Census/MapServer">
<esri:ArcGISDynamicMapServiceLayer.DynamicLayerInfos>
<esri:DynamicLayerInfoCollection>
<esri:DynamicLayerInfo ID="2">
<esri:DynamicLayerInfo.Source>
<esri:LayerMapSource MapLayerID="2" />
</esri:DynamicLayerInfo.Source>
</esri:DynamicLayerInfo>
</esri:DynamicLayerInfoCollection>
</esri:ArcGISDynamicMapServiceLayer.DynamicLayerInfos>
</esri:ArcGISDynamicMapServiceLayer>