[Users] GeoExt.MapPanel and TabPanel

[Luca Casagrande]

Hello folks,
I have some troubles with GeoExt.MapPanel and Ext.TabPanel (the code
is at the end of the message):
- if I set as activeTab the one with the map, it doesn't load the
overlay layers and firebug says:

tile is undefined
[Break on this error] tile.unload();\nGrid.js (riga 563)
bottomLeftTile is undefined
[Break on this error] bounds = new
OpenLayers.Bounds(bottomLeftTile.bounds.left, \n

- if I set as activeTab the other one, all is fine.
Can this be related to DOM loading?

Thanks
Ciao
Luca

Code:
var  mapTab = new Ext.TabPanel({
                                 region: 'center',
                                 deferredRender: false,
                                 activeTab: 0,
                                 items: [{
                                           html: '<p>Test</p>',
                                           title:'Welcome!',
                                           closable: false,
                                           autoScroll: true
                                         },
                                           new GeoExt.MapPanel({
                                               title: ' Test',
                                               closable : false,
                                               map: new
OpenLayers.Map(options),
                                               center: [lon, lat],
                                               zoom: 0,
                                               layers: [..]
                                          })]
});