title: Ext.form.combobox inside ext.window displays values at top left of screen
body: <p>I have a combobox inside of a ext.panel, inside of an ext.window. When I click the down arrow to show the possible SELECT options, the options pop up at the top-left of the browser window, instead of below the SELECT box. The funny thing is if I attach the drugDetailsPanel (see code below) to a div on the page (instead of inside an ext.window), the combobox works correctly. This also happens when I change ext.panel to ext.form.formpanel, by the way.</p>
  
  <p>Any ideas?</p>
  
  <p>My code:</p>
  
  <pre><code>drugDetailsPanel = new Ext.Panel({
   layout:'form',
   id:'drug-details-panel',
   region:'center',
   title:'Drug Details',
   height:200,
   collapsed:false,
   collapsible:false,
   items:[
           new Ext.form.ComboBox({
  
            fieldLabel:'What is the status of this drug?',
            typeAhead:false,
         store:drugStatusStore, 
         displayField:'lookup', 
         mode:'remote', 
         triggerAction:'all',
         editable:false,
         allowBlank:false,
         emptyText:'Select a status..',
         name:'/drug/drug-status',
         id:'drug-status'
        })
  
   ]       
  });
  
  newDrugWindow = new Ext.Window({
      title: 'Add Drug',
      closable:true,
      width:650,
      height:650,
      //border:false,
      plain:true,
      layout: 'border',
      items: [drugDetailsPanel],
    closeAction:'hide',
    modal:true,
    buttons: [
     {
      text:'Close',
      disabled:false,
      handler: function(){
      newDrugWindow.hide();
      }
     },
     {
      text:'Save Drug',
      handler: function(){
        newDrugDialog.hide();
      }
    }]
      });
  </code></pre>