On FireFox 3.5, with Ext 3.0 and the matching ManagedIframe class, the following code works as expected to create tabs with IFRAME's for the content of each.

However, it also places the 2nd IFRAME containing the second URL under the tabs. This is then removed once a tab is picked.

Any ideas why this may be happening ? A google around hasn't turned up this happening...

Code:
Ext.onReady(function(){    

var tabpanel2 = new Ext.TabPanel({
    tabPosition:'left',
    activeTab: 0,
    tabWidth:110,
    height:"480",
    renderTo:'tabs2',
    defaults:{autoScroll: true},
    
    items:[
        {
            title:"Generate X
            body:new Ext.ux.ManagedIframe({autoCreate:{ src:"/x.cfm", frameBorder: 0, cls:'x-panel-body',width: '99%', height: 480}})
          },
        {
            title:"Y details",
              body:new Ext.ux.ManagedIframe({autoCreate:{ src:"/y.cfm", frameBorder: 0, cls:'x-panel-body',width: '99%', height: 480}})
        },
        {
            title:'Z report',
            html:'TBC'
        },
        {
            title:'Narrative',
            html:'TBC'
        }
    ]
  });
    
});//onReady