Run the following test
and click several times to JTabbedPane's body
and you'll see JTabbedPane tabs are getting corrupted


import javax.swing.*;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;

public class TabbedTest {
    public static void main(String[] args) {
        JFrame frame = new JFrame();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        final JTabbedPane pane = new JTabbedPane();
        pane.add("", null);
        pane.add("", null);
        pane.add("", null);
        pane.add("", null);

        final JLabel label = new JLabel("JLabel");
        pane.setTabComponentAt(2, label);

        frame.add(pane);

        pane.addMouseListener(new MouseAdapter() {
            public void mouseClicked(MouseEvent e) {
                label.setText(label.getText() + " !");
            }
        });

        frame.setSize(200, 200);
        frame.setVisible(true);
    }
}