(1) Working environments
OS : Solaris 2.5.1, 2.6, 2.7 Japanese version
JRE : jdk 1.1.6 fcs, 1.1.8, 1.2.1_03
Window : CDE

(2) Phenomenon
Java application program MemLeak.java, that create and destroy Panel
in thread on Frame.
Invoke MemLeak and a few minutes after, The heap in the jre process is
going on increasing. Check the pmap command during an hour, increasing
by 1.5 kbytes per second.

-- MemLeak.java --
import java.awt.*;

public class MemLeaks extends Frame implements Runnable {
     MemLeaks() {
          setSize(800, 800);
          setVisible(true);

          new Thread(this).start();
     }

     public void run(){
          while(true){
               Panel panel = new Panel();
               add(panel);
               panel.repaint();

               try {
                    System.gc();
                    Thread.sleep(100);
               }
               catch (InterruptedException e) {}

               remove(panel);
          }
     }

     public static void main(String[] args){
          new MemLeaks();
     }
}