title: TypeError: b is undefined in Firefox when update store content
body: <p>I am trying to update some grid columns when I select an option from a combobox (that is in the first column of the same grid), I am getting this error on Firefox with Firebug:</p>
  
  <blockquote>
    <p>TypeError: b is undefined</p>
  </blockquote>
  
  <p>By the way I'm using <strong>Extjs 4.2</strong></p>
  
  <p>This is my code</p>
  
  <pre><code>    onComboboxSelect: function(combo, records, eOpts) {
  
      var grid = this.getGrillaFE();
      var store = grid.getStore();
  
      if( grid.getSelectionModel().hasSelection() )
      {
          var row = grid.getSelectionModel().getSelection()[0];
          console.log(row);
  
          //I got the error here:
          row.set("IdEmpresa", records[0].data.Id);
  
         //row.set("Contacto", records[0].data.Contacto);
  
         //row.set("Celular", records[0].data.Celular);
     }
      });
  </code></pre>
  
  <p>So when I check the value of row... it is updated with the new id, but I'm getting that error. So, is it ok? Or am I forgetting something?</p>
  
  <p>Thank you in advance</p>