When the following application is run under Mac OS X, DRAG_DROPPED never appears in the output. The output consists only of DRAG_OVER events:

===== DRAG_OVER =====
system mode: null
source modes: []
accepted modes: null
WARNING: unhandled case in mapNsOperationToJavaMask: 0 [on thread "0x0x7fff7adb3960", is main:1]
===== DRAG_OVER =====
system mode: null
source modes: []
accepted modes: null
WARNING: unhandled case in mapNsOperationToJavaMask: 0 [on thread "0x0x7fff7adb3960", is main:1]

etc.

On Windows with the latest JavaFX 2.0.2, the output is as expected:

===== DRAG_OVER =====
system mode: MOVE
source modes: [COPY, MOVE, LINK]
accepted modes: MOVE
===== DRAG_OVER =====
system mode: MOVE
source modes: [COPY, MOVE, LINK]
accepted modes: MOVE
===== DRAG_DROPPED =====
Dropped: [C:\Users\Dean Iverson\Documents\ca\DragDrop2.jar]

The code is as follows:

public class DragDrop1 extends Application {

  public static void main(String[] args) {
    launch(args);
  }

  @Override
  public void start(Stage primaryStage) {
    Rectangle rect = new Rectangle(100, 100);
    rect.setId("dragTarget");

    rect.setOnDragOver(new EventHandler<DragEvent>() {
      @Override
      public void handle(DragEvent event) {
        System.out.println("===== DRAG_OVER =====");
        System.out.println("system mode: "+event.getTransferMode());
        Dragboard db = event.getDragboard();
        System.out.println("source modes: "+db.getTransferModes());
        if (db.hasFiles()) {
          event.acceptTransferModes(TransferMode.ANY);
          System.out.println("accepted modes: "+event.getAcceptedTransferMode());
        }
        event.consume();
      }
    });

    rect.setOnDragDropped(new EventHandler<DragEvent>() {
      @Override
      public void handle(DragEvent event) {
        System.out.println("===== DRAG_DROPPED =====");
        Dragboard db = event.getDragboard();
        boolean success = false;
        if (db.hasFiles()) {
          System.out.println("Dropped: " + db.getFiles());
          success = true;
        }
        event.setDropCompleted(success);
        event.consume();
      }
    });
    
    final StackPane root = new StackPane();
    root.getChildren().add(rect);
    
    final Scene scene = new Scene(root);
    final URL stylesheet = getClass().getResource("media.css");
    scene.getStylesheets().add(stylesheet.toString());
    
    primaryStage.setScene(scene);
    primaryStage.setTitle("Audio Player 2");
    primaryStage.show();
  }
}