Run the attached program.
  - Select Look & Feel.
  - Execute addItem by "ADD" button.
  - and repeat addItem.

Then, the following exception is occurred.
  Exception occurred during event dispatching:
  java.lang.ArrayIndexOutOfBoundsException: xx
  at com.sun.java.swing.plaf.basic.BasicListUI.convertRowToY(Compiled Code)
:
:

When Look & Feel is not specified, this exception is not occurred.
But you select Look & Feel once, this exception is sure to be occurred.

Program : ComboTest.java
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import com.sun.java.swing.*;
import java.awt.*;
import java.util.*;
import java.awt.event.*;

public class ComboTest extends JFrame implements WindowListener, ActionListener, ItemListener {
JComboBox combo;

public ComboTest() {
super("Combo Test");

combo = new JComboBox();
combo.addActionListener(this);
combo.addItemListener(this);
combo.setEditable(true);
combo.addItem("Item 1");
combo.addItem("Item 2");
combo.addItem("Item 3");
this.getContentPane().setLayout(new FlowLayout());
this.getContentPane().add(combo);
JButton button = new JButton("ADD");
button.addActionListener(this);
this.getContentPane().add(button);

UIManagerMenu uim = new UIManagerMenu();
uim.setMenuBar(this);

setBounds(0,0,300,150);
addWindowListener(this);
setVisible(true);
}

public void actionPerformed(ActionEvent e) {
if (e.getActionCommand().compareTo("ADD") == 0) {
combo.addItem(combo.getEditor().getItem());
}
}

public void itemStateChanged(ItemEvent e) {

}

public void windowOpened(WindowEvent e) {}
public void windowClosing(WindowEvent e) {
System.exit(0);
}
public void windowClosed(WindowEvent e) {}
public void windowIconified(WindowEvent e) {}
public void windowDeiconified(WindowEvent e) {}
public void windowActivated(WindowEvent e) {}
public void windowDeactivated(WindowEvent e) {}

public static void main(String args[]) {
ComboTest ct = new ComboTest();
}
}
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UIManagerMenu.java
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import java.awt.*;
import com.sun.java.swing.*;
import java.awt.event.*;

public class UIManagerMenu implements ActionListener{
private Component parent = null;

public UIManagerMenu(){
}

public void setMenuBar(JFrame frame){
this.parent = frame;
JMenuBar menubar = new JMenuBar();
frame.setJMenuBar(menubar);
this.setMenu(menubar, frame);
}

public void setMenu(JMenuBar menubar, JFrame frame){
JMenu menu = new JMenu();
menu = new JMenu("LookAndFeel");
        menu.setMnemonic('L');
menubar.add(menu);

this.parent = frame;

UIManager.LookAndFeelInfo[] uiinfo = UIManager.getInstalledLookAndFeels();
String laf = UIManager.getLookAndFeel().getID();

JRadioButtonMenuItem rb;
ButtonGroup rg = new ButtonGroup();
for(int i = 0; i < uiinfo.length; i++){
rb = new JRadioButtonMenuItem( uiinfo[i].getName() );
menu.add(rb);
rg.add(rb);
rb.setActionCommand( uiinfo[i].getClassName() );
rb.addActionListener(this);

if (uiinfo[i].getName().compareTo(laf) == 0)
rb.setSelected(true);
}
}

public void actionPerformed(ActionEvent event) {
String action = event.getActionCommand();
try{
UIManager.setLookAndFeel(action/*ClassName*/);
SwingUtilities.updateComponentTreeUI(this.parent);
}catch(Exception e){
System.out.println("action setLookAndFeel err: " + e);
e.printStackTrace();
}
}
}
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