Applet, double buffering og det haker alligevel

Jeg har en simpel applet, der har en firkant jeg kan styre med piletasterne rundt i vinduet. Jeg bruger double buffering, men den hakker alligevel.... WAS IST LOS?

Herunder ses min updatemetode: fundet herpå eksperten leveret af disky:
public void update( Graphics g )
    {
        if (dbon)
        {
            updateDoubleBufffered( g );
        }
        else
        {
            super.update( g );
        }
    }
   
    // Do the drawing to an offscreen buffer -- maybe
    private void updateDoubleBufffered( Graphics g )
    {
       
        // Let\'s make sure we have an offscreen buffer, and that
        // it\'s the right size.  If the applet has been resized,
        // our buffer will be the wrong size and we need to make
        // a new one
        Dimension d = getSize();
        if (offscreen == null || width!=d.width || height!=d.height || offscreen==null)
        {
            width = d.width;
            height = d.height;
            if (width>0 || height>0)
            {
                offscreen = createImage( width, height );
            }
            else
            {
                offscreen = null;
            }
        }
       
        // If we still don\'t have one, give up
        if (offscreen == null) return;
       
        // Get the off-screen graphics object
        Graphics gg = offscreen.getGraphics();
       
        // Clear the off-screen graphics object
        gg.setColor( getBackground() );
        gg.fillRect( 0, 0, width, height );
        gg.setColor( getForeground() );
       
        // Draw to the off-screen graphics object
        paint( gg );
       
        // We don\'t need this Graphics object anymore
        gg.dispose();
       
        // Finally, we transfer the newly-drawn stuff right to the
        // screen
        g.drawImage( offscreen, 0, 0, null );
    }