J2ME Exception - PLEASE HELP

I am bit of a newbie to J2ME, and I am trying to create a simple
metronome application. I am using Java 1.4.2.16 along with the Sun
WTK.
I am getting an exception as:

java.lang.IllegalArgumentException: type media does not have subtype
Tone
    at com.sun.kvem.warn.DefaultWarnUserPolicy.shouldWarnUser(Unknown
Source)
    at com.sun.kvem.warn.UserWarningManager.warnUser(Unknown Source)
    at sun.reflect.GeneratedMethodAccessor13.invoke(Unknown Source)
    at
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:
25)
    at java.lang.reflect.Method.invoke(Method.java:324)
    at com.sun.kvem.Lime$Connection.callMethod(Unknown Source)
    at com.sun.kvem.Lime$Connection.processCommand(Unknown Source)
    at com.sun.kvem.Lime$Connection.run(Unknown Source)
    at java.lang.Thread.run(Thread.java:534)

The source code is included below:
import java.util.*;
import java.io.*;
import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
import javax.microedition.media.*;
import javax.microedition.media.Manager;
import javax.microedition.media.control.*;

public class TestMIDlet extends MIDlet implements CommandListener
{
   private boolean started = false;
   private Thread thread = null;
   private int timerInterval = 0;
   private Timer timer = null;
   private TimerTask task = null;
   private static List theList = null;
  /* private static Vector urls = null; */
   private Command exitCommand = new Command("Exit", Command.EXIT, 1);
   private Command playCommand = new Command("Play", Command.ITEM, 1);
   private Display display = null;

   public TestMIDlet ()
   {
     super();
     display = Display.getDisplay(this);
     initPlayList();
     display.setCurrent(theList);
     String interval = getAppProperty("Timer-Interval");
     timerInterval = 3000; Integer.parseInt(interval);
     System.out.println("Midlet started ... timer interval is "
+timerInterval);
   }

   public static List getList() {
    return theList;
    }

   protected void startApp()
   {
     if(!started)
     {
       started = true;
       startTimer();
     }
     else
     {
       System.out.println("Eat pussy now ...");
     }

     synchronized(this)
     {

      if(thread == null)
      {

        thread = new Thread()
        {

          public void run()
          {

           System.out.println("Thread started ...");
            while(thread == this)
            {
              try
              {
                  Thread.sleep(5000);
              }
              catch(InterruptedException ie)
              {
              }
            }
            System.out.println("Thread terminating ...");

          }

        };

       }

      };
      thread.start();

    }

    protected void pauseApp()
    {
      System.out.println("pauseApp invoked ...");
      synchronized(this)
      {
       if(thread != null)
       {
        thread = null;
       }
     }
    }

    public void commandAction(Command c, Displayable s)
    {
    if (c == exitCommand)
        {
          try
           {
        destroyApp(true);
        notifyDestroyed();
           }
           catch(MIDletStateChangeException msce)
           {
           }
    }

        else if ((s == theList &&
                 c == List.SELECT_COMMAND) ||
         c == playCommand)
        {

        if (theList.getSelectedIndex() == 0)
            { // Simple tone
              for(;;)
              {
        try
                {
          Manager.playTone(90, 200, 90);
        } catch (MediaException ex) {
            System.out.println("can't play tone");
        }
              }
        }
    }
    }

    protected void destroyApp(boolean unconditional) throws
MIDletStateChangeException
    {
      System.out.println("destroyApp called ... unconditional =
"+unconditional);
      if(thread != null)
      {
        Thread bgthread = thread;
        thread = null;
        try
        {
         bgthread.join();
        }
        catch(InterruptedException ie){}
       }
      stopTimer();
      display.setCurrent(null);
    }

   private void stopTimer()
   {
     if(timer != null)
     {
       timer.cancel();
       System.out.println("Timer stopped ...");
     }
   }

   private void startTimer()
   {

     task = new TimerTask(){
       private boolean isPaused = false;
       private int count = 0;

       public void run()
       {
        if(count++ == 4)
        {
         try
         {
           TestMIDlet.this.destroyApp(true);
         }
         catch(MIDletStateChangeException msche)
         {
         }
         TestMIDlet.this.notifyDestroyed();
         return;
        }

       if(isPaused)
       {
         TestMIDlet.this.resumeRequest();
         isPaused = false;
        }

       else
       {
         isPaused = true;
         TestMIDlet.this.pauseApp();
         TestMIDlet.this.notifyPaused();
       }
       /*
       try
       {
         System.out.println("trying to play sound");
         Manager.playTone(60, 200, 90);
       }
       catch(MediaException mex)
       {
         System.out.println("Can't play the fuckin' sound ...");
       }
       */
      }
     };

    timer = new Timer();
    timer.schedule(task, timerInterval, timerInterval);
  }

  private void initPlayList()
  {
        /*urls = new Vector(); */

    theList = new List("Pussy Milk", Choice.IMPLICIT);
        /*
    for (int n = 1; n < 32; n++)
        {
        String nthURL = "PlayerURL-"+ n;
        String url = getAppProperty(nthURL);
        if (url == null || url.length() == 0) {
        break;
        }
        String nthTitle = "PlayerTitle-" + n;
        String title = getAppProperty(nthTitle);
        if (title == null || title.length() == 0) {
        title = url;
        }
        urls.addElement(url);
        theList.append(title, null);
    }
        */
        theList.append("Play", null);
    theList.addCommand(exitCommand);
    theList.addCommand(playCommand);
    theList.setCommandListener(this);
  }

 }

Any hints would be extremely useful. Thanks in advance for your help.