Drop handler is now giving correct feedback to drag source.

src/AddIns/DisplayBindings/WpfDesign/WpfDesign.Designer/Project/Services/CreateComponentTool.cs

@@ -123,6 +123,10 @@ namespace ICSharpCode.WpfDesign.Designer.Services
 					moveLogic.DesignPanel.IsAdornerLayerHitTestVisible = true;
 					moveLogic = null;
 					changeGroup.Commit();
+
+					// Return allowed effects to drag source to signal that the drop was successful.
+					e.Effects = e.Effects;
+					e.Handled = true;
 				}
 			} catch (Exception x) {
 				DragDropExceptionHandler.RaiseUnhandledException(x);