Program: 51570
Project: 51570
Buggy source:
/** 
 * The toolbar for the control panel - open, layer and run The buttons have matching menu items performing the same actions 
 */
private void createToolbar(){
  int iconSize=20;
  JToolBar toolbar=new JToolBar();
  toolbar.setFloatable(false);
  toolbar.setRollover(true);
  toolbar.setPreferredSize(new Dimension(0,iconSize + 20));
  URL imgURL=getClass().getResource("String_Node_Str");
  ImageIcon iconOpen=new ImageIcon(imgURL);
  Image img=iconOpen.getImage().getScaledInstance(iconSize,iconSize,Image.SCALE_SMOOTH);
  iconOpen.setImage(img);
  JButton buttonOpen=new JButton(iconOpen);
  buttonOpen.setSize(iconSize,iconSize);
  buttonOpen.setToolTipText("String_Node_Str");
  buttonOpen.setActionCommand("String_Node_Str");
  buttonOpen.addActionListener(this);
  toolbar.add(buttonOpen);
  imgURL=getClass().getResource("String_Node_Str");
  ImageIcon iconBringToFront=new ImageIcon(imgURL);
  img=iconBringToFront.getImage().getScaledInstance(iconSize,iconSize,Image.SCALE_SMOOTH);
  iconBringToFront.setImage(img);
  JButton buttonBringToFront=new JButton(iconBringToFront);
  buttonBringToFront.setSize(iconSize,iconSize);
  buttonBringToFront.setToolTipText("String_Node_Str");
  buttonBringToFront.setActionCommand("String_Node_Str");
  buttonBringToFront.addActionListener(this);
  toolbar.add(buttonBringToFront);
  imgURL=getClass().getResource("String_Node_Str");
  ImageIcon iconReloadAndRun=new ImageIcon(imgURL);
  img=iconReloadAndRun.getImage().getScaledInstance(iconSize,iconSize,Image.SCALE_SMOOTH);
  iconReloadAndRun.setImage(img);
  JButton buttonReloadAndRun=new JButton(iconReloadAndRun);
  buttonReloadAndRun.setSize(iconSize,iconSize);
  buttonReloadAndRun.setToolTipText("String_Node_Str");
  buttonReloadAndRun.setActionCommand("String_Node_Str");
  buttonReloadAndRun.addActionListener(this);
  toolbar.add(buttonReloadAndRun);
  frame.add(toolbar,BorderLayout.NORTH);
}

Fixed version (ground truth):
/** 
 * The toolbar for the control panel - open, layer and run The buttons have matching menu items performing the same actions 
 */
protected void createToolbar(){
  int iconSize=20;
  JToolBar toolbar=new JToolBar();
  toolbar.setFloatable(false);
  toolbar.setRollover(true);
  toolbar.setPreferredSize(new Dimension(0,iconSize + 20));
  URL imgURL=getClass().getResource("String_Node_Str");
  ImageIcon iconOpen=new ImageIcon(imgURL);
  Image img=iconOpen.getImage().getScaledInstance(iconSize,iconSize,Image.SCALE_SMOOTH);
  iconOpen.setImage(img);
  JButton buttonOpen=new JButton(iconOpen);
  buttonOpen.setSize(iconSize,iconSize);
  buttonOpen.setToolTipText("String_Node_Str");
  buttonOpen.setActionCommand("String_Node_Str");
  buttonOpen.addActionListener(this);
  toolbar.add(buttonOpen);
  imgURL=getClass().getResource("String_Node_Str");
  ImageIcon iconBringToFront=new ImageIcon(imgURL);
  img=iconBringToFront.getImage().getScaledInstance(iconSize,iconSize,Image.SCALE_SMOOTH);
  iconBringToFront.setImage(img);
  JButton buttonBringToFront=new JButton(iconBringToFront);
  buttonBringToFront.setSize(iconSize,iconSize);
  buttonBringToFront.setToolTipText("String_Node_Str");
  buttonBringToFront.setActionCommand("String_Node_Str");
  buttonBringToFront.addActionListener(this);
  toolbar.add(buttonBringToFront);
  imgURL=getClass().getResource("String_Node_Str");
  ImageIcon iconReloadAndRun=new ImageIcon(imgURL);
  img=iconReloadAndRun.getImage().getScaledInstance(iconSize,iconSize,Image.SCALE_SMOOTH);
  iconReloadAndRun.setImage(img);
  buttonReloadAndRun=new JButton(iconReloadAndRun);
  buttonReloadAndRun.setEnabled(false);
  buttonReloadAndRun.setSize(iconSize,iconSize);
  buttonReloadAndRun.setToolTipText("String_Node_Str");
  buttonReloadAndRun.setActionCommand("String_Node_Str");
  buttonReloadAndRun.addActionListener(this);
  toolbar.add(buttonReloadAndRun);
  frame.add(toolbar,BorderLayout.NORTH);
}