I have now a dragging source and a dragging destination in one application. When I drag from the source to the target view with the same application, draggingEntered is called. When I open a second instance of the application and drag from the source view of the first application instance to the target view of the other application instance, draggingEntered is not called. When I drag from Finder.app to either of the target views draggingEntered is called. I am puzzled. Where is my mistake?