Universal Image Loader giving error loading image

I want to load images from Url with universal image loader, but the error:

  

java.lang.NoClassDefFoundError:   com.nostra13.universalimageloader.core.ImageLoaderConfiguration $ Builder

I've already downloaded the lib, and set it up.

My adapter:

  public class AdapterEmpresa extends BaseAdapter {

    private LayoutInflater mInflater;
    private List<Segmento> itens;

    ImageLoader imageLoader;
    DisplayImageOptions options;

    public AdapterEmpresa(Context context, List<Segmento> itensEmpresa) {
        //Itens que preencheram o listview
        super();
        this.itens = itensEmpresa;

        ImageLoaderConfiguration config = new ImageLoaderConfiguration.Builder(context).build();
        imageLoader = ImageLoader.getInstance();
        imageLoader.init(config);

        options = new DisplayImageOptions.Builder()
        .cacheInMemory()
        .cacheOnDisc()
        .build();
        //responsavel por pegar o Layout do item.
        mInflater = LayoutInflater.from(context);
    }



    /**
     * Retorna a quantidade de itens
     * 
     * @return
     */
    public int getCount() {
        return itens.size();
    }

    /**
     * Retorna o item de acordo com a posicao dele na tela.
     *
     * @param position
     * @return
     */
    public Segmento getItem(int position) {
        return itens.get(position);
    }

    /**
     * Sem implementação
     *
     * @param position
     * @return
     */

    public long getItemId(int position) {
        return position;
    }

    public View getView(int position, View view, ViewGroup parent) {
        //Pega o item de acordo com a posção.
        LinearLayout row = (LinearLayout)view;
        Segmento item = itens.get(position);
        //infla o layout para podermos preencher os dados
        view = mInflater.inflate(R.layout.empresa_item, null);
        //atravez do layout pego pelo LayoutInflater, pegamos cada id relacionado
        //ao item e definimos as informações.
        final ImageView iconImg = (ImageView)row.findViewById(R.id.imagemSegmento);
        TextView nome = (TextView)row.findViewById(R.id.nomeEmpresa);
        TextView subtitulo = (TextView)row.findViewById(R.id.subtitulo);
        final ProgressBar indicator = (ProgressBar)row.findViewById(R.id.progress);

        indicator.setVisibility(View.VISIBLE);
        iconImg.setVisibility(View.INVISIBLE);


        ImageLoadingListener listener = new ImageLoadingListener(){

            @Override
            public void onLoadingCancelled(String arg0, View arg1) {
                // TODO Auto-generated method stub

            }

            @Override
            public void onLoadingComplete(String arg0, View arg1, Bitmap arg2) {
                indicator.setVisibility(View.INVISIBLE);
                iconImg.setVisibility(View.VISIBLE);
            }

            @Override
            public void onLoadingFailed(String arg0, View arg1, FailReason arg2) {
                // TODO Auto-generated method stub

            }

            @Override
            public void onLoadingStarted(String arg0, View arg1) {
                // TODO Auto-generated method stub

            }
        };
        imageLoader.displayImage(getItem(position).getImagem(), iconImg,options, listener);
      //Set the relavent text in our TextViews
      nome.setText(getItem(position).getNome());
      subtitulo.setText(getItem(position).getSubtitulo());
      return row;


}

I'm calling the Adapter like this:

adapterEmpresa = new AdapterEmpresa(EmpresaView.this, itensEmpresa);

just passing the list, because the Image String is already in the list.

Does anyone know what it can be?