Barre de progression dans la listview tout AsyncTask téléchargement de fichier

J'ai un étrange problème, j'ai un nouveau asynctask launced chaque fois que je trouve un fichier MP3 sur webbrowser, et lance une barre de progression dans la liste pour chaque AsyncTask. Si nombre de téléchargements peut être supérieur à 1 et simultanée. Mais maintenant, chaque fois que Asynctask est launced ProgressBar se déplace même pour tous et pas pour différentes AsyncTask, Plz me guider.......

    public class CopyOfDownloadsListActivity extends ListActivity {
/** Called when the activity is first created. */
// static ArrayList<String> pthreads = new ArrayList<String>();
ImageView bt;
ProgressBar pb;
ListView allList;
TextView tv;
String fileName;
String mp3URL;
URL url2;
int filecount  = 0;
private class DownloadFile extends AsyncTask<String, Integer, Void>{
MyCustomAdapter adapter;
int count = 0;
ProgressDialog dialog;
ProgressBar progressBar;
int myProgress;
@Override        
protected Void doInBackground(String... u) {        
try {                   
URL ul = new URL(u[0]);
Log.i("UI",ul.toString());
//  int len = CopyOfMusicDownloader.mp3urls.size();
//  URL url2 = new URL(CopyOfMusicDownloader.mp3urls.get(len-1));
HttpURLConnection c = (HttpURLConnection) ul.openConnection();
c.setRequestMethod("GET");
c.setDoOutput(true);
c.connect();
int lengthOfFile = c.getContentLength();
String PATH = Environment.getExternalStorageDirectory()
+ "/download/";
Log.v("", "PATH: " + PATH);
File file = new File(PATH);
file.mkdirs();
fileName = "Track";
filecount++;
fileName =  fileName + Integer.toString(filecount) + ".mp3";
File outputFile = new File(file, fileName);
FileOutputStream fos = new FileOutputStream(outputFile);
InputStream is = c.getInputStream();
byte[] buffer = new byte[1024];
int len1 = 0;      
while ((len1 = is.read(buffer)) != -1) {
myProgress = (int)((len1/lengthOfFile)*100);
myProgress = myProgress + myProgress;
Log.i("lengthOfFile", Integer.toString(lengthOfFile));
Log.i("My Progress", Integer.toString(myProgress));
publishProgress(myProgress);
fos.write(buffer, 0, len1);
}
fos.close();
is.close();
}catch (IOException e) {
e.printStackTrace();
}
return null;
}
protected void onPostExecute() {
}
@Override
protected void onPreExecute() {         
adapter = new MyCustomAdapter(CopyOfDownloadsListActivity.this, R.layout.row, CopyOfMusicDownloader.mp3urls);
setListAdapter(adapter);
}
@Override
protected void onProgressUpdate(Integer... values) {
Log.i("Value", values[0].toString());
count++;
adapter.notifyDataSetChanged();
}
public class MyCustomAdapter extends ArrayAdapter<String> {     
public MyCustomAdapter(Context context, int textViewResourceId, ArrayList<String> pthreads) {
super(context, textViewResourceId, pthreads);
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
LayoutInflater inflater = getLayoutInflater();
View row = inflater.inflate(R.layout.row, parent, false);
bt =(ImageView)row.findViewById(R.id.cancel_btn);
tv =(TextView)row.findViewById(R.id.filetext);
pb = (ProgressBar)row.findViewById(R.id.progressbar_Horizontal);
pb.setProgress(count);  
return row;
}
}       
}  

C'est l'AsyncTask démarrer, et son onCreate
nouveau DownloadFile().execute(url2.toString());