A DESCRIPTION OF THE REGRESSION :
Menu parts overlapping heavyweight components being partially outside the main window don't properly react to mouse gestures.

REPRODUCIBLE TESTCASE OR STEPS TO REPRODUCE:
// store code in Menu.java, compile and run

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class Menu
{
    public JMenuBar createMenuBar()
    {
        ActionListener l = new ActionListener()
            {
                public void actionPerformed(ActionEvent e)
                { System.out.println("Ouch!"); }
            };

        JMenuBar b = new JMenuBar();

        JMenu m = new JMenu("A Menu");
        b.add(m);

        JMenuItem i = new JMenuItem("A menu item",KeyEvent.VK_A);
        m.add(i);
        i.addActionListener(l);

        m = new JMenu("Another Menu");
        b.add(m);
        i = new JMenuItem("Yet another menu item",KeyEvent.VK_Y);
        m.add(i);
        i.addActionListener(l);

        return b;
    }

    private static void createAndShowGUI()
    {

        JFrame frame = new JFrame("Menu");
        Menu m = new Menu();
        frame.setJMenuBar(m.createMenuBar());
        frame.setSize(200, 200);
        frame.setVisible(true);
    }

    public static void main(String[] args)
    {
        javax.swing.SwingUtilities.invokeLater(new Runnable()
            { public void run() { createAndShowGUI(); }});
    }
}


RELEASE LAST WORKED:
5.0 Update 6

RELEASE TEST FAILS:
mustang-b70

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
- Compile and run the code below on Java 5 Update 6, a window with two menus opens.

- Klick "Another Menu", and move the pointer, keeping the left mouse button still pressed, onto the menu's
  single item, "Yet another menu item".
- The highlight jumps from "Another Menu" to "Yet another menu item". This is correct.
- Release the mouse button (pointer still over "Yet another menu item").
- The menu closes and the handler is called (printing "Ouch!" to the shell). As expected.
- Move the pointer over "A Menu" (all buttons still released).
- Nothing happens. That's fine.
ACTUAL -
- Run the code below on Mustang build 70, a window with two menus opens.

- Klick "Another Menu", and move the pointer, keeping the left mouse button still pressed, onto the menu's
  single item, "Yet another menu item".
- "Another Menu" is still highlighted., the menu item "Yet another menu item" doesn't get the highlight: just wrong.
- Release the mouse button (pointer still over "Yet another menu item").
- Nothing happens. Weird.
- Move the pointer over "A Menu" (all buttons still released).
- The menu pops down. Not as expected.