Program: 21306
Project: 21306
Buggy source:
public JHelpDialog(JFrame frame,final String title,String html,final int countdown){
  super(frame);
  parentFrame=frame;
  setLayout(new GridBagLayout());
  this.setModal(false);
  setBtn1(new JButton("String_Node_Str"));
  setBtn2(new JButton("String_Node_Str"));
  setBtn3(new JButton("String_Node_Str"));
  btn4=new JButton(JDLocale.L("String_Node_Str","String_Node_Str"));
  getBtn1().addActionListener(this);
  getBtn2().addActionListener(this);
  getBtn3().addActionListener(this);
  btn4.addActionListener(this);
  setTitle(title);
  htmlArea=new JTextPane();
  htmlArea.setEditable(false);
  htmlArea.setContentType("String_Node_Str");
  htmlArea.setText(html);
  htmlArea.setOpaque(false);
  htmlArea.requestFocusInWindow();
  setComponentOrientation(ComponentOrientation.RIGHT_TO_LEFT);
  Icon imageIcon=new ImageIcon(JDUtilities.getImage(JDTheme.V("String_Node_Str")));
  JDUtilities.addToGridBag(this,new JLabel(imageIcon),0,0,1,1,0,0,insets,GridBagConstraints.NONE,GridBagConstraints.NORTHWEST);
  JDUtilities.addToGridBag(this,htmlArea,1,0,3,1,1,1,insets,GridBagConstraints.BOTH,GridBagConstraints.NORTHWEST);
  JDUtilities.addToGridBag(this,getBtn1(),2,1,1,1,1,0,insets,GridBagConstraints.NONE,GridBagConstraints.NORTHEAST);
  JDUtilities.addToGridBag(this,getBtn2(),3,1,1,1,0,0,insets,GridBagConstraints.NONE,GridBagConstraints.NORTHEAST);
  JDUtilities.addToGridBag(this,getBtn3(),4,1,1,1,0,0,insets,GridBagConstraints.NONE,GridBagConstraints.NORTHEAST);
  if (countdown > 0) {
    JDUtilities.addToGridBag(this,btn4,1,1,1,1,0,0,insets,GridBagConstraints.NONE,GridBagConstraints.NORTHEAST);
    countdownThread=new Thread(){
      @Override public void run(){
        int c=countdown;
        while (--c >= 0 && stopTimer == false) {
          if (countdownThread == null)           return;
          setTitle(title + "String_Node_Str" + JDUtilities.formatSeconds(c)+ "String_Node_Str");
          try {
            Thread.sleep(1000);
          }
 catch (          InterruptedException e) {
          }
          if (!isVisible())           return;
        }
        if (stopTimer == false) {
          dispose();
        }
 else {
          setTitle(title);
        }
      }
    }
;
    countdownThread.start();
  }
  pack();
  getRootPane().setDefaultButton(getBtn1());
  setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);
}

Fixed version (ground truth):
public JHelpDialog(JFrame frame,final String title,String html,final int countdown){
  super(frame);
  parentFrame=frame;
  setLayout(new GridBagLayout());
  this.setModal(false);
  setBtn1(new JButton("String_Node_Str"));
  setBtn2(new JButton("String_Node_Str"));
  setBtn3(new JButton("String_Node_Str"));
  btn4=new JButton(JDLocale.L("String_Node_Str","String_Node_Str"));
  getBtn1().addActionListener(this);
  getBtn2().addActionListener(this);
  getBtn3().addActionListener(this);
  btn4.addActionListener(this);
  setTitle(title);
  htmlArea=new JTextPane();
  htmlArea.setEditable(false);
  htmlArea.setContentType("String_Node_Str");
  htmlArea.setText(html);
  htmlArea.setOpaque(false);
  htmlArea.requestFocusInWindow();
  setComponentOrientation(ComponentOrientation.RIGHT_TO_LEFT);
  Icon imageIcon=new ImageIcon(JDUtilities.getImage(JDTheme.V("String_Node_Str")));
  JDUtilities.addToGridBag(this,new JLabel(imageIcon),0,0,1,1,0,0,insets,GridBagConstraints.NONE,GridBagConstraints.NORTHWEST);
  JDUtilities.addToGridBag(this,htmlArea,1,0,3,1,1,1,insets,GridBagConstraints.BOTH,GridBagConstraints.NORTHWEST);
  JDUtilities.addToGridBag(this,getBtn1(),2,1,1,1,1,0,insets,GridBagConstraints.NONE,GridBagConstraints.NORTHEAST);
  JDUtilities.addToGridBag(this,getBtn2(),3,1,1,1,0,0,insets,GridBagConstraints.NONE,GridBagConstraints.NORTHEAST);
  JDUtilities.addToGridBag(this,getBtn3(),4,1,1,1,0,0,insets,GridBagConstraints.NONE,GridBagConstraints.NORTHEAST);
  if (countdown > 0) {
    JDUtilities.addToGridBag(this,btn4,1,1,1,1,0,0,insets,GridBagConstraints.NONE,GridBagConstraints.NORTHEAST);
    countdownThread=new Thread(){
      @Override public void run(){
        int c=countdown;
        while (--c >= 0 && stopTimer == false) {
          if (countdownThread == null)           return;
          setTitle(title + "String_Node_Str" + JDUtilities.formatSeconds(c)+ "String_Node_Str");
          try {
            Thread.sleep(1000);
          }
 catch (          InterruptedException e) {
          }
          if (!isVisible())           return;
        }
        if (stopTimer == false) {
          dispose();
        }
 else {
          setTitle(title);
        }
      }
    }
;
    countdownThread.start();
  }
  pack();
  getRootPane().setDefaultButton(getBtn1());
  setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);
  this.setAlwaysOnTop(true);
}