FULL PRODUCT VERSION :
java version "1.6.0_10-beta"
Java(TM) SE Runtime Environment (build 1.6.0_10-beta-b24)
Java HotSpot(TM) Client VM (build 11.0-b12, mixed mode, sharing)

ADDITIONAL OS VERSION INFORMATION :
Microsoft Windows XP [Version 5.1.2600]
Microsoft Windows 2003 Server

EXTRA RELEVANT SYSTEM CONFIGURATION :
My graphic card is Intel 865G, but I think this problem has nothing to do with graphic card.

A DESCRIPTION OF THE PROBLEM :
Screen flickers when a JFrame switches to fullscreen mode. My program works properly in J2SE5, J2SE6update2, J2SE6Update5, therefore I conclude that it's J2SE6 Update 10's problem.

I guess the possible cause is: 1. the repaint event was not handled properly.
2. SetVisble(false) does not work propoerly.

I have to write a demo program to show this problem. hope it will be helpful.



STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
1. Save the source code as "AppMain.java"
2. Compile it.
3. Run it with J2SE6U10: "java AppMain"
4. Choose the Menu "File-->FullScreen(Esc to cancel)"


EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
The screen should switch to fullscreen immediately and smoothly.


ACTUAL -
The screen does not switch to full screen mode smoothly.
It flickers several times.


REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
import java.awt.*;
import java.util.*;
import java.awt.event.*;
import javax.swing.*;
import java.io.*;
import java.util.*;


public class AppMain {

  public static void main (String[] args) {

  // define frame, its size and make it visible
  int arg0=-1;


  AppletFrame myFrame = new AppletFrame();

  myFrame.setVisible(true);

  } // end main method
} // end class


class AppletFrame extends JFrame implements ActionListener, WindowListener, MouseListener, MouseMotionListener, KeyListener {
  private MenuBar mb=null;
  private SpringLayout layout=null;
  private Dimension d0=null, d1=null;
  private boolean fullscreenOn=false;
  private int itemcounter=0;
  private boolean noSnapShot= true;
  private String[] xmlname;
  private String[] trackname;
  private int[] initTrack;
  private int trackCounter=1;
  private boolean fromlocaldir=false;
  private String[] localfilelist=null;
  private String autoplay="enable";
  private String strokemode="disable";
  private boolean debug=false;
  private ImageIcon jtvicon=null;
  private JFileChooser _fileChooser1;

  public AppletFrame(boolean debug)
  {
super("SlidePlayer"); // use SlidePlay as window title
this.debug=debug;
initFrame();
  }
  public AppletFrame()
  {
super("SlidePlayer"); // use SlidePlay as window title
initFrame();
  }

  public void initFrame() {



    this.getContentPane().setBackground(Color.black);

    // define Menubar
    mb = new MenuBar();
// mb.setFont(new Font("Helvetica", Font.PLAIN, 13));

    setMenuBar(mb);
    // Define File menu and with Exit menu item
    Menu fileMenu = new Menu("File");

    
    MenuItem exitMenuItem = new MenuItem("Exit");
    MenuItem fullscreenMenuItem = new MenuItem("Fullscreen (Esc to cancel)");
    


    //exitMenuItem.setAccelerator( KeyStroke.getKeyStroke("alt F4") );
    fileMenu.add(exitMenuItem);
    fileMenu.add(fullscreenMenuItem);



    // respond to file exit/fullscreen menu
    exitMenuItem.addActionListener(this);
    fullscreenMenuItem.addActionListener(this);



    // respond to window events
    addWindowListener(this);
    addKeyListener(this); // Respond to keystroke

    

    mb.add(fileMenu);

    JLabel t1= new JLabel("Hello");
    this.add(t1);

    this.setLayout(new BorderLayout());


    this.setPreferredSize(new Dimension(640, 480));

    pack();

    getContentPane().setBackground(Color.blue);
    d0= this.getSize();
System.out.println("d0:"+ d0);

    
    setVisible(true); // usual step to make frame visible

    requestFocus();
    requestFocusInWindow();
    requestFocus();
    setResizable(false);
  



  } // end main


  public void destroy()
  {
System.exit(1);
  }


  public void actionPerformed(ActionEvent evt) {

    if (evt.getSource() instanceof MenuItem) {
      String menuLabel = ((MenuItem)evt.getSource()).getLabel();

      if(menuLabel.equals("Exit")) {
        // close application, when exit is selected
        dispose();
        System.exit(0);
      } // end if



      if(menuLabel.equals("Fullscreen (Esc to cancel)")) {

setVisible(false);

setMenuBar(null);
dispose();
setUndecorated(true);
 
// switching to fullscreen mode
GraphicsEnvironment.getLocalGraphicsEnvironment().getDefaultScreenDevice().setFullScreenWindow(this);
 
// getting display resolution: width and height
int w = this.getWidth();
int h = this.getHeight();


setPreferredSize(new Dimension(w, h));
getContentPane().setBackground(Color.blue);


this.setVisible(true);
// requestFocus();
// requestFocusInWindow();
// requestFocus();
repaint();

fullscreenOn=true;


      } // end if
}


  } // end ActionPerformed

   public void keyPressed(KeyEvent evt) {

    int key = evt.getKeyCode();
         // escape key to exit from fullscreen mode
if (key == KeyEvent.VK_ESCAPE) { // switching to window when press Escape key
if(fullscreenOn==true)
{

// switching to window mode
setVisible(false);
GraphicsEnvironment.getLocalGraphicsEnvironment().getDefaultScreenDevice().setFullScreenWindow(null);

  setMenuBar(mb);
dispose();
setUndecorated(false);

this.setLayout(new BorderLayout());
this.setPreferredSize(d0);
pack();
 
// window should be visible
this.setVisible(true);
fullscreenOn=false;
repaint();
}

}

   }

   public void keyReleased(KeyEvent evt) {}
   public void keyTyped(KeyEvent evt) {}


public void windowClosing(WindowEvent e) {
System.exit(1);
    }
    
    public void windowClosed(WindowEvent e) {
        //This will only be seen on standard output.
    }
    
    public void windowOpened(WindowEvent e) {
    }
    
    public void windowIconified(WindowEvent e) {
    }
    
    public void windowDeiconified(WindowEvent e) {
    }
    
    public void windowActivated(WindowEvent e) {
    }
    
    public void windowDeactivated(WindowEvent e) {
    }

   

   public void mouseDragged(MouseEvent e) {}

   public void mouseMoved(MouseEvent e) {}

// detect double click and single click
   public void mouseClicked( MouseEvent e ) {}

   public void mouseEntered( MouseEvent e ) { }
   public void mouseExited( MouseEvent e ) { }
   public void mousePressed( MouseEvent e ) { }
   public void mouseReleased( MouseEvent e ) { }

} // end class



---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
No workaround so far. I have to use J2SE6 Update 5

Release Regression From : 6u5
The above release value was the last known release where this
bug was not reproducible. Since then there has been a regression.