It happens 80% of the time using Mozilla when the dialog is cancelled but less frequent in IE and appletviewer.

Here is the code that demonstrates the problem:

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

public class AWTPrintTest extends JApplet implements Printable {
    private JButton jButton1 = new JButton();


    public AWTPrintTest() {
    }

    public void init() {
        try {
            jbInit();
        }
        catch(Exception e) {
            e.printStackTrace();
        }
    }

    private void jbInit() throws Exception {
        jButton1.setText("PRINT");
        jButton1.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(ActionEvent e) {
                jButton1_actionPerformed(e);
            }
        });
      jButton1.setBounds(new Rectangle(165, 248, 80, 30));
        this.setSize(new Dimension(400,300));
      this.getContentPane().setLayout(null);
      this.getContentPane().setBackground(Color.pink);
        this.getContentPane().add(jButton1, BorderLayout.SOUTH);
    }

    public void start() {
    }

    public void stop() {
    }

    public void destroy() {
    }

    public String getAppletInfo() {
        return "Applet inf";
    }

    public String[][] getParameterInfo() {
        return null;
    }

   public void paint(Graphics g) {
      super.paint(g);
      g.setColor(Color.black);
      g.drawString("Hello World", 20, 100);
   }

   public int print(Graphics g, PageFormat pf, int page) throws PrinterException {
      return Printable.NO_SUCH_PAGE;
   }

    void jButton1_actionPerformed(ActionEvent e) {
      PrinterJob printJob = null;
      PageFormat pageFormat = null;
      boolean bPrintFlg = true;
   
      try{
         printJob = PrinterJob.getPrinterJob();

      }
      catch(SecurityException se){

         bPrintFlg = false;
      }

      if (bPrintFlg) {

printJob.pageDialog(printJob.defaultPage());
System.out.println("AWTPrintTest: getActiveWindow after pageDialog = "+KeyboardFocusManager.
getCurrentKeyboardFocusManager().getActiveWindow());
         
        printJob.printDialog();
System.out.println("AWTPrintTest: getActiveWindow after printDialog = "+KeyboardFocusManager.
getCurrentKeyboardFocusManager().getActiveWindow());
      }
    }
}
=============