JTable fails to draw Column Header if first header is assigned an empty string

Build : 'I' (last build work: 'A', unable to test B, C failed in 'D')
          according to our 2D eng build bringovers, it worked on 19-May but
          failed on 20-May.
OS : all platforms.
app : Java2Demo.jar (sub demo: Intro)
          execution: java -cp Java2Demo.jar Intro
          {right click on border to get to the JTable}

This particular panel calls up a lightweight JTable with Column Headers, but headers fails to appear.


import javax.swing.JTable;
import javax.swing.JScrollPane;
import javax.swing.JPanel;
import javax.swing.JFrame;
import java.awt.*;
import java.awt.event.*;

public class ColHeaderBug extends JFrame {

    public ColHeaderBug() {super("ColHeaderBug");

        Object[][] data = {
{"r1c1", "col2", "col3"},
{"r2c1", "col2", "col3"},
{"r3c1", "col2", "col3"},
{"r4c1", "col2", "col3"},
        };

        String[] columnNames = {"",
                                "Column 2",
                                "Column 3"};

        final JTable table = new JTable(data, columnNames);
        table.setPreferredScrollableViewportSize(new Dimension(200, 100));
        JScrollPane scrollPane = new JScrollPane(table);
        getContentPane().add(scrollPane, BorderLayout.CENTER);

        addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent e) {
                System.exit(0);
            }
        });
    }


    public static void main(String[] args) {
        ColHeaderBug frame = new ColHeaderBug();
        frame.pack();
        frame.setVisible(true);
    }
}