Problem GameCanvas for Nokia 6260!!!!

Question

Hi,
I tested some applications that extends the GameCanvas, when I tested on simulator J2ME Wireless Toolkit it hasn't problem when I download the application on phone (Nokia 6260) the program show screen and it work ok but when i try go out the application send the two errors
"Buffer closed java.lang.RunTimeException
0 java.lang.NullPointerException"
It's possible that phone not support the class javax.microedition.lcdui.game.GameCanvas? or what's the problem?
Help me please,
Thanks
P.S Below put the code, maybe this way is easer.
// A simple example of a game canvas that displays
// a scrolling star field. The UP and DOWN keys
// speed up or slow down the rate of scrolling.
public class StarField extends GameCanvas implements Runnable{
     private static final int SLEEP_INCREMENT = 10;
     private static final int SLEEP_INITIAL = 150;
     private static final int SLEEP_MAX = 300;
     private Graphics graphics;
     private Random random;
     private int sleepTime = SLEEP_INITIAL;
     private volatile Thread thread;
     private Command salir = null;
     public StarField(){
          super( true );
          graphics = getGraphics();
          graphics.setColor( 0, 0, 0 );
          graphics.fillRect( 0, 0, getWidth(), getHeight() );
     // When the game canvas is hidden, stop the thread.
     protected void hideNotify(){
          thread = null;
     // The game loop.
     public void run(){
          int w = getWidth();
          int h = getHeight() - 1;
          while( thread == Thread.currentThread() ){
               // Increment or decrement the scrolling interval
               // based on key presses
               int state = getKeyStates();
               if( ( state & DOWN_PRESSED ) != 0 ){
                    sleepTime += SLEEP_INCREMENT;
                    if( sleepTime > SLEEP_MAX )
                         sleepTime = SLEEP_MAX;
               } else if( ( state & UP_PRESSED ) != 0 ){
                    sleepTime -= SLEEP_INCREMENT;
                    if( sleepTime < 0 ) sleepTime = 0;
               // Repaint the screen by first scrolling the
               // existing starfield down one and painting in
               // new stars...
               graphics.copyArea( 0, 0, w, h, 0, 1,
               Graphics.TOP | Graphics.LEFT );
               graphics.setColor( 0, 0, 0 );
               graphics.drawLine( 0, 0, w, 1 );
               graphics.setColor( 255, 255, 255 );
               for( int i = 0; i < w; ++i ){
                    int test = Math.abs( random.nextInt() ) % 10;
                    if( test < 4 ){
                         graphics.drawLine( i, 0, i, 0 );
               flushGraphics();
               // Now wait...
               try {
                    Thread.currentThread().sleep( sleepTime );
               catch( InterruptedException e ){
     // When the canvas is shown, start a thread to
     // run the game loop.
     protected void showNotify(){
          random = new Random();
          thread = new Thread( this );
          thread.start();
Thanks, see you

Answer 1

do you have a memory card in your phone? Try freeing up your phones memo by deleting text,images and videos
If  i have helped at all a click on the white star below would be nice thanks.
Now using the Lumia 1520