A DESCRIPTION OF THE REGRESSION :
In the latest Mustang builds, on Windows XP Home with Service Pack 2, disabled javax.swing.JButton components have an unsightly one-pixel-thick black border around them.

REPRODUCIBLE TESTCASE OR STEPS TO REPRODUCE:

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


public class DisabledButtonTest {

    public static void main(String[] args) throws Exception {
	UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
	
	JButton disabledButton = new JButton("Disabled Button");
	disabledButton.setEnabled(false);
	
	JPanel panel = new JPanel(new FlowLayout());
	panel.add(new JButton("Enabled Button"));
	panel.add(disabledButton);
	
	JFrame frame = new JFrame();
	frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
	frame.getContentPane().add(panel);
	
	frame.pack();
	frame.setLocationRelativeTo(null);
	frame.setVisible(true);
    }

}


RELEASE LAST WORKED:
5.0 Update 6

RELEASE TEST FAILS:
mustang-b70

APPLICATION NAME: Zion Software's JBuddy Messenger	APPLICATION VERSION: Any version

APPLICATION NAME: Netbeans	APPLICATION VERSION: Any version

OBSERVED APPLICATION IMPACT:
Applications under Windows XP will stand out in a bad way, as disabled buttons stand out more with the incorrect border.  It will give users the impression that Java applications are not at home on the desktop.