title: How to manage PagingToolbar in Ext-js 4.2 correctly?
body: <p>js 4.2), and I've got some problems when I manage a toolbar on  a grid which use a Proxy (ajax).</p>
  
  <pre><code> this.grid  = new Ext.create('Ext.grid.Panel',{
              region      : 'center',
              loadMask    : true,
              layout      : 'fit',
              store       : 'Contenedores',
  
              tbar: [
                     { text: 'Exportar Excel' },
                     '-&gt;',
                     { text:'Buscar',     handler: this.buscar,   scope: this},
                     '-',
                     { text:'Limpiar',    handler: this.limpiar,  scope: this}
              ],
              columns : [],
  
              bbar : new Ext.create('Ext.toolbar.Paging',{
                  store: 'Contenedores', displayInfo: true,
                  displayMsg  : 'Registros {0} - {1} de {2}',
                  emptyMsg    : 'No hay registros'
              })
          });
  </code></pre>
  
  <p>The problems, I'm having are:</p>
  
  <ul>
  <li>When I call to store.load(), pagingToolbar doesn't block so I can click on the next page, and when the grid is loaded I get the incorrect page on pagingtoolbar. On Ext js 3 when I se loadMask: true on the grid, the pagingToolbar gets locked when I call store.load().</li>
  <li>If I'm on a page like 2 or higher and I call to store.load(), pagingToolbar doesn't update, after loading, the current page label to 1.</li>
  <li>I need to implement a clean/reset button, so how can I clean the labels on the pagingtoolbar.</li>
  </ul>
  
  <p>thanks in advance.</p>