FULL PRODUCT VERSION :
java version "1.6.0_01"
Java(TM) SE Runtime Environment (build 1.6.0_01-b04)
Java HotSpot(TM) Server VM (build 1.6.0_01-b04, mixed mode)

ADDITIONAL OS VERSION INFORMATION :
Windows XP SP2

A DESCRIPTION OF THE PROBLEM :
When I call addComponentListner to a component which is in a JScrollPane, the ComponentEvents are never received. If I add the component without a JScollPane, the event is fired. A component should receive events whether or not it is in a JScrollPane.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Run the program detailed in "executable test case". Click on tab labeled "1" and then on tab labeled "2".

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
Clicking on tab "1" writes "componentShown: taOne" to System.out.
Clicking on tab "2" writes "componentShown: taTwo" to System.out.
ACTUAL -
Clicking on tab "1" writes "componentShown: taOne" to System.out.
Clicking on tab "2" writes nothing.

ERROR MESSAGES/STACK TRACES THAT OCCUR :
No errors.

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.ComponentAdapter;
import java.awt.event.ComponentEvent;
import java.awt.event.KeyEvent;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;

import javax.swing.Box;
import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JDialog;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTabbedPane;
import javax.swing.JTextArea;

public class Test extends JDialog
{
  private JButton btnOK;

  public Test(JFrame parent) {
    super(parent, "Test", true);
    init();
  }

  private void init() {
    JPanel pnlMain = new JPanel(new BorderLayout(5, 5));

    JTextArea taOne = new JTextArea(5, 20);
    JTextArea taTwo = new JTextArea(5, 20);
    JTabbedPane tabPane = new JTabbedPane();
    tabPane.addTab("0", new JLabel("1"));
    tabPane.addTab("1", taOne);
    tabPane.addTab("2", new JScrollPane(taTwo));
    pnlMain.add(tabPane, BorderLayout.CENTER);
    pnlMain.add(getButtonPanel(), BorderLayout.SOUTH);

    taOne.addComponentListener(new ComponentAdapter() {
      public void componentShown(ComponentEvent e) {
        System.out.println("componentShown: taOne");
      }
    });

    taTwo.addComponentListener(new ComponentAdapter() {
      public void componentShown(ComponentEvent e) {
        System.out.println("componentShown: taTwo");
      }
    });

    this.setContentPane(pnlMain);
    this.pack();
    this.setLocationRelativeTo(this.getOwner());
    rootPane.setDefaultButton(btnOK);

    this.setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);
  }

  private JPanel getButtonPanel() {
    JPanel pnlButtons = new JPanel();
    pnlButtons.setLayout(new BoxLayout(pnlButtons, BoxLayout.X_AXIS));

    btnOK = new JButton("OK");
    btnOK.setMnemonic(KeyEvent.VK_S);
    pnlButtons.add(Box.createHorizontalGlue());
    pnlButtons.add(btnOK);
    pnlButtons.add(Box.createHorizontalGlue());

    btnOK.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent e) {
        Test.this.dispose();
      }
    });

    return pnlButtons;
  }

  public static void main(String[] args) {
    JFrame frame = new JFrame();
    frame.setFocusable(false);
    frame.setResizable(false);
    frame.setUndecorated(true);
    frame.setBounds(0, 0, 0, 0);
    final Test dialog = new Test(frame);
    frame.setTitle(dialog.getTitle());
    frame.addWindowFocusListener(new WindowAdapter() {
      public void windowGainedFocus(WindowEvent ev) {
        // since frame has no size, dialog should get focus instead of frame
        dialog.toFront();
        dialog.requestFocus();
      }
    });
    frame.setVisible(true);
    dialog.setVisible(true);
    frame.setVisible(false);
    System.exit(0);
  }
}
---------- END SOURCE ----------