app/code/local/Aoe/Layout/Block/Widget/Tabs.php
public function addTab($tabId, $tab)
    {
        parent::addTab($tabId, $tab);

        if ($this->_tabs[$tabId] instanceof Mage_Core_Block_Abstract && $this->_tabs[$tabId]->getParentBlock() === null) {
            $this->append($this->_tabs[$tabId]);
        }

        return $this;
    }
public function addTab($tabId, $tab)
    {
        parent::addTab($tabId, $tab);

        if ($this->_tabs[$tabId] instanceof Mage_Core_Block_Abstract && $this->_tabs[$tabId]->getParentBlock() === null) {
            $this->append($this->_tabs[$tabId]);
        }

        return $this;
    }
public function addTab ( $ tabId , $ tab ) { parent :: addTab ( $ tabId , $ tab ) ; if ( $ this -> _tabs [ $ tabId ] instanceof Mage_Core_Block_Abstract && $ this -> _tabs [ $ tabId ] -> getParentBlock ( ) === null ) { $ this -> append ( $ this -> _tabs [ $ tabId ] ) ; } return $ this ; }
Add new tab

@param   string $tabId
@param   array|Varien_Object $tab
@return  Mage_Adminhtml_Block_Widget_Tabs
Add new tab