Here is the code that demonstrates the bug.

import java.awt.*;

public class AlwaysOnTop { 

    public static void main(String[] args) {
     
     Frame f = new Frame("Frame");
     f.setBounds(100,100,400,400);

     f.show();
   
     // Always on Top seems to not work on Windows if the Dialog 
     // is modal
     Dialog d = new Dialog(f,"Dialog",true);
     d.setAlwaysOnTop(true);
     d.setBounds(200,200,400,400);
     d.show();
      
     
    }


}