The program below illustrates a bug with SwingUtilities.getDeepestComponentAt():
(this method is provided as an alternative to Container.findComponentAt)

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.Color;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import javax.swing.JFrame;
import javax.swing.JTabbedPane;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;

public class FolderTest extends JFrame {

        public FolderTest() {
                super("Folder Test");
        }

        public static void main(String args[]) {
                FolderTest test = new FolderTest();
                test.setSize(new Dimension(200, 200));

                JTabbedPane tabbedpane = new JTabbedPane();
                test.setContentPane(tabbedpane);

                JPanel panel1 = new JPanel();
                panel1.setName("Panel 1");
                panel1.setLayout(new BorderLayout());
                tabbedpane.add(panel1);
                JPanel subPanel = new JPanel();
                subPanel.setName("Sub-Panel");
                subPanel.setBackground(Color.green);
                panel1.add(subPanel); // add sub panel to 1st tab

                JPanel panel2 = new JPanel();
                panel2.setName("Panel 2");
                tabbedpane.add(panel2);

                tabbedpane.setSelectedIndex(1); // display 2nd tab
                test.setVisible(true);

                // incorrectly finds sub panel (currently hidden in panel 1)...should return
                // panel 2
                //System.out.println(tabbedpane.findComponentAt(50,50).getName());
                System.out.println(SwingUtilities.getDeepestComponentAt(tabbedpane, 50, 50).getName());
        }
}