画面一闪而过的问题

[I_am_a_java_CaiNiao]

大家好，我做了个精灵类的简单测试，就是把一幅图片分割，但启动后，模拟器一闪而过，请问这是怎么回事，谢谢。
代码：

package sprite;

import javax.microedition.lcdui.Display;
import javax.microedition.lcdui.Command;
import javax.microedition.lcdui.CommandListener;
import javax.microedition.lcdui.Displayable;
import javax.microedition.midlet.MIDlet;
import javax.microedition.midlet.MIDletStateChangeException;

public class SpriteTest extends MIDlet implements
		CommandListener
{
	private Command cmdExit;
	private SpriteCanvas sc;

	public SpriteTest()
	{
		sc = new SpriteCanvas();
		cmdExit = new Command("Exit", Command.EXIT, 1);
		sc.addCommand(cmdExit);
		sc.setCommandListener(this);
	}

	protected void destroyApp(boolean arg0)
			throws MIDletStateChangeException
	{
	}

	protected void pauseApp()
	{
	}

	protected void startApp()
			throws MIDletStateChangeException
	{
		Display.getDisplay(this).setCurrent(sc);
	}

	public void commandAction(Command cmd, Displayable da)
	{
		if (cmd == cmdExit)
		{
			try
			{
				destroyApp(false);
			} catch (Exception e)
			{}
			notifyDestroyed();
		}
	}
}

package sprite;

import javax.microedition.lcdui.Graphics;
import javax.microedition.lcdui.Image;
import javax.microedition.lcdui.game.GameCanvas;
import javax.microedition.lcdui.game.Sprite;

public class SpriteCanvas extends GameCanvas implements
Runnable
{
private int width;
private int height;
private int startX;
private int startY;
private Sprite sprite;
private Image spriteImage;
private Graphics g;
private static final int[] frameOrder = { 0, 1, 2 };

protected SpriteCanvas()
{
super(true);
width = getWidth();
height = getHeight();
startX = 0;
startY = 0;
try
{
spriteImage = Image.createImage("/T.png");
} catch (Exception e)
{
}
g = getGraphics();
sprite = new Sprite(spriteImage, 32, 48);
sprite.setFrameSequence(frameOrder);
new Thread(this).start();
}

public void run()
{
while (true)
{
g.setColor(0x000000);
g.fillRect(0, 0, width, height);
sprite.nextFrame();
if (startY + 5 < height)
{
startY += 5;
sprite.setPosition(startX, startY);
} else
{
startY = 0;
sprite.setPosition(startX, startY);
}

sprite.paint(g);
flushGraphics();
}
}
}

[吐泡泡的鱼]

模拟器一闪而过，是自己关了吗？
那有可能是配置的问题吧，代码没有问题。