Run the following code and click the label to create a popup-menu. For the first time, nothing will happen; Repeat it once again, then an unexpected exception occurs and a core dump is generated. This is found happening in SunOS5.7, Solaris 8.0 and SolarisX86 8.0.
A similar problem found in JComboBox popup, obviously.

Code snippet:
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class FrameDemo extends JFrame {
    public FrameDemo() {
setSize(300, 300);
        addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent e) {
                System.exit(0);
            }
        });
        
        //adding JPasswordField
        final JLabel label = new JLabel("Right-click herefor popup");
        final JPopupMenu pMenu = new JPopupMenu();
        pMenu.add("FirstMenu");
        label.addMouseListener(new MouseAdapter(){
          public void mousePressed(MouseEvent e) {
            pMenu.show(label, e.getX(), e.getY());
          }
        });
        
        getContentPane().add(label, BorderLayout.CENTER);
    }
    public static void main(String s[]) {
      FrameDemo fd = new FrameDemo();
      fd.pack();
      fd.setVisible(true);
    }
}

Exception seen on console:
# # An unexpected exception has been detected in native code outside the VM.# Program counter=0xf5e4d488
#
# Problematic Thread: prio=5 tid=0x1167e0 nid=0xc runnable
#
Abort (core dumped)