Windows XP with dolphin:

Compile and run the program below. Notice that it calls setDynamicLayout(false). Notice that it prints out that dynamic layout is NOT active. However, when resizing the frame, dynamic layout IS active.

This is not reproducible in 6.0.

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

public class LayoutTest extends JFrame implements ActionListener {
    
    private JComboBox lafCombo;
   
    public LayoutTest() {
        lafCombo = new JComboBox(new String[] {"Ocean",
                                               "Steel",
                                               "Windows",
                                               "Motif",
                                               "GTK"});
        lafCombo.addActionListener(this);
        JPanel bottom = new JPanel();
        bottom.add(lafCombo);
        getContentPane().add(bottom, BorderLayout.SOUTH);
    }
    
    public void actionPerformed(ActionEvent ae) {
    }

    public static void main(String[] args) {
        Toolkit.getDefaultToolkit().setDynamicLayout(false);
        System.out.println(Toolkit.getDefaultToolkit().isDynamicLayoutActive());

        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                LayoutTest test = new LayoutTest();
                test.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                test.setSize(200, 200);
                test.setLocationRelativeTo(null);
                test.setVisible(true);
            }
        });
    }
}