title: ExtJs IE7: 'events is null or not an object' when I closed window
body: <p>I am using grid component, when users double click on records - open window, here is my code:</p>
  
  <pre><code>var gridPanel = Ext.create('AB.ins.Grid', {
      title:'Grid Panel',
      allowBlank: true,
      style: {
        cursor: 'default'
      },
      store: insuranceStore,
      columns: [
        {header:'№', dataIndex: 'id',width: 45, align: 'right'},
        {header:'Name', dataIndex: 'fio', width: 250},
      ],
      dockedItems: [{
        xtype: 'pagingtoolbar',
        store: insuranceStore,
        itemId: 'pagingbar',
        dock: 'bottom',
        displayInfo: true
      }],
      listeners: {
        itemdblclick: function(obj,record,item,index,event,options) {      
          var testshow = Ext.create('Ext.Window', {
            width: 500,
            height: 600,
            modal: true,
            title: 'Test window'
          });
          testshow.show();
        }
      }
  });
  </code></pre>
  
  <p>In FF this code works fine. In IE7 this code works, but when i closed window in the third or fourth time IE show errors 'events is null or not an object'. What occurs?</p>