Using Mustang build-62 an Applet that extends JApplet fails to re-draw as expected when moved around the screen. Extending from Applet works fine and running the following code under Tiger works fine. The problem can be reproduced using the Appletviewer.

The code that fails:
public class MyApplet extends JApplet {
    public void paint(Graphics g) {
        g.drawString("Hello World!", 50, 25);
    }
}

A link to a sample Applet:
      http://dispesable.east/Applets/HelloWorld.htm