(keitai-l) hang up when a sound is played

Hello, I have a problem. When I play a sound, application hangs. The 
application only plays the sound once. Can anybody give me a hint about 
what is happening? I am using this code

import com.nttdocomo.ui.*;
import com.nttdocomo.io.*;

public class clase1 extends IApplication{
        public void start(){

        sonido miSonido = new sonido();

        }
}

class sonido  {

        private AudioPresenter Bs;

        public sonido(){
                MediaSound s;

        s = MediaManager.getSound("resource:///n31.mld");
        try{
        s.use();
        }catch (ConnectionException e){}
        Bs = AudioPresenter.getAudioPresenter();
        Bs.setSound(s);
        Bs.play();
        Bs.play();
        Bs.play();
        }

}