fieldcontainer layout bug type 'HBox' ....
when I put a textfield and a button is like the image below ...
Captura de tela de 2012-07-25 16:08:54.png

follows the code ...

HTML Code:
{
                            xtype: 'fieldcontainer',
                            autoHeight: true,
                            hideLabel: true,
                            layout: {
                                align: 'stretch',
                                type: 'hbox'
                            },
                            items: [
                                {
                                    xtype: 'textfield',
                                    name: 'cabo_fibra_nome',
                                    id: 'cabo_fibra_id_splitter_porta_nome',                                                                                                                                                                    
                                    readOnly: true,
                                    flex: 1,
                                    anchor: '100%',
                                    fieldLabel: 'Cabo Fibra'
                                },
                                {
                                    xtype: 'button',
                                    hidden: true,
                                    id: 'cabo_fibra_id_splitter_porta_button',
                                    margins: '15 0 0 5',
                                    iconCls: 'bt_cancel'
                                }
                            ]
                        }