setIgnoreRepaint(true) only works once

FULL PRODUCT VERSION :
D:\jdk1.5\bin>java -version
java version "1.5.0_09"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_09-b03)
Java HotSpot(TM) Client VM (build 1.5.0_09-b03, mixed mode, sharing)

ADDITIONAL OS VERSION INFORMATION :
Microsoft Windows 2000 [Version 5.00.2195]

A DESCRIPTION OF THE PROBLEM :
setIgnoreRepaint(true) works great once. If I setIgnoreRepaint(false) then setIgnoreRepaint(true) in sequence, then the component is repainted on any and all paint events.

I setIgnoreRepaint(true) to draw multiple times into a Canvas without flicker. Then setIgnoreRepaint(false) so that expose events are handled. Subsequently, if I again setIgnoreRepaint(true) -- that doesn't stop paint() events from being received by my Canvas.



STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
setIgnoreRepaint(true)

<do some rapid drawing>

setIgnoreRepaint(false)

<handle some expose events>

setIgnoreRepaint(false)

<do some rapid drawing and notice flicker from paint() events being handled.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
I expect to stop paint() event caused flicker yet be able to handle expose events inbetween drawing actions.
ACTUAL -
setIgnoreRepaint(true) works only the first time. Subsequent setIgnoreRepaint(true) don't work.

ERROR MESSAGES/STACK TRACES THAT OCCUR :
No error messages.

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
package pancyl;

import java.awt.*;
import java.awt.image.*;


public class PanCylProjector
{
    private BufferedImage image = null;
    private BufferedImage subImage = null;
    private Raster raster = null;
    private WritableRaster dataRas = null;
    private WritableRaster midRas = null;
    private WritableRaster leftRas = null;
    private WritableRaster rightRas = null;
    private WritableRaster subRaster = null;
    private ColorModel cm = null;
    private int imageW, imageH = 0;
    private int canvasW, canvasH = 0;
    private double RADIUS = 0.0;
    private DataBuffer dataBuffer = null;
    private PanCylCanvas canvas = null;
    private int viewPointX, viewPointY = 0;
    private int dx, dy = 0;
    private int canvasCenterX, canvasCenterY = 0;
    private int halfCanvasW, halfCanvasH = 0;
    private double MAXDX, MAXDY = 0.0;
    private int subImageX, subImageY = 0;
    private double MOVEFACTOR = 0.05;
    private int leftX, leftW, rightX, rightW = 0;
    public PanCylProjector()
    {
        // TODO Auto-generated constructor stub
    }
    public void setCanvas(PanCylCanvas c)
    {
        canvas = c;
        canvasW = canvas.getWidth();
        canvasH = canvas.getHeight();
        halfCanvasW = canvasW / 2;
        halfCanvasH = canvasH / 2;
        canvasCenterX = (int)((canvasW / 2.0) + 0.5);
        canvasCenterY = (int)((canvasH / 2.0) + 0.5);
    }
    public void setImage(BufferedImage i)
    {
        if(PanCylApplet.DEBUG)
            System.err.println("Projector: setting image");
        image = i;
        imageW = image.getWidth();
        imageH = image.getHeight();
        MAXDX = imageW * MOVEFACTOR;
        MAXDY = imageH * MOVEFACTOR;
        viewPointX = (int)((imageW / 2.0) + 0.5);
        viewPointY = (int)((imageH / 2.0) + 0.5);
        subImageX = viewPointX - halfCanvasW;
        subImageY = viewPointY - halfCanvasH;

        RADIUS = imageW / (2.0 * Math.PI);
        cm = image.getColorModel();
        raster = (WritableRaster)image.getRaster();
        subRaster = (WritableRaster)image.getData(new Rectangle(subImageX, subImageY, canvasW, canvasH));
        subRaster = subRaster.createWritableTranslatedChild(0, 0);
        canvas.setSubRaster(subRaster);
        canvas.repaint();
    }
    public boolean mouseDown = false;
    public int mouseX, mouseY = 0;
    public void setMouseDown(boolean b)
    {
        mouseDown = b;
        System.err.println("setMouseDown(" + b + ")");
        if(mouseDown)
        {
            canvas.setIgnoreRepaint(true);
            Runnable r = new Runnable()
            {
                public void run()
                {
                    canvas.setIgnoreRepaint(true);
                    mouseEvent();
                    canvas.setIgnoreRepaint(false);
                }
            };
            new Thread(r).start();
        }
        else
            canvas.setIgnoreRepaint(false);
    }
    public void setMousePosition(int x, int y)
    {
        mouseX = x;
        mouseY = y;
    }

    public void mouseEvent()
    {
        
        while (mouseDown == true)
        {
            try
            {
                Thread.yield();
                Thread.sleep(10);
                subImageX += (int) ((((double) mouseX - (double) halfCanvasW) / (double) canvasW) * MAXDX);
                subImageY += (int) ((((double) mouseY - (double) halfCanvasH) / (double) canvasH) * MAXDY);
                if ((subImageY + canvasH) > imageH)
                    subImageY = imageH - canvasH - 1;
                if ((subImageY) < 0)
                    subImageY = 0;
                if (subImageX < 0)
                    subImageX = imageW + subImageX;
                if (subImageX > (imageW - 1))
                    subImageX = subImageX - imageW;
                //System.err.println("subImageX = " + subImageX + ", subImageY = " + subImageY);
                if ((subImageX + canvasW) >= imageW)
                {
                    leftW = imageW - subImageX;
                    rightW = canvasW - leftW;
                    leftRas = (WritableRaster) raster.createChild(subImageX, subImageY, leftW, canvasH, 0, 0, null);
                    rightRas = (WritableRaster) raster.createChild(0, subImageY, rightW, canvasH, 0, 0, null);
                    subRaster.setRect(0, 0, leftRas);
                    subRaster.setRect(leftW, 0, rightRas);
                    canvas.setSubRaster(subRaster);
                    canvas.repaint();

                }
                else
                {
                    midRas = (WritableRaster) raster.createChild(subImageX, subImageY, canvasW, canvasH, 0, 0, null);
                    canvas.setSubRaster(midRas);
                    canvas.repaint();
                }
            }
            catch (InterruptedException e)
            {
                System.err.println("Exception in mouseEvent()");
            }
        }
    }
}
---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
None that I can figure out.