How do I move my JMenuBar to the screen menu bar on Mac OS X?

Question

When I move my JMenuBar to the screen menu bar on Mac OS X, it leaves some blank space where the menu would be in my window; I need to remove that space. I am using

System.setProperty("apple.laf.useScreenMenuBar", "true")

to move my JMenuBar to the screen menu bar. My friend who uses a Mac reports that this leaves some ugly vertical space where the menu would reside if I did not set that property. What is the best way to resolve this issue?

EDIT: Here is an example from my source:

public static void main(String[] args) {
    System.setProperty("apple.laf.useScreenMenuBar", "true");
    System.setProperty("com.apple.mrj.application.apple.menu.about.name", "Name");

    JFrame frame = new JFrame("Gabby");
    final DesktopMain dm = new DesktopMain();

    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.add(dm);
    frame.setSize(160, 144);
    frame.setLocationRelativeTo(null);
    frame.setIgnoreRepaint(true);

    JMenuBar menuBar = new JMenuBar();
    JMenu fileMenu = new JMenu("File");
    menuBar.add(fileMenu);

    // Populating the menu bar code goes here

    frame.setJMenuBar(menuBar);
    frame.setVisible(true);
}