Custom Manager: Form Validation Problem with Tabs and MODx.window

MODx.window.CreateBoatsData = function(config) {
    config = config || {};
    Ext.applyIf(config,{
		id: 'modx-window-boats-create'
        ,title: _('wmg.boats.create')
        ,baseParams: { action: 'boats_create'}
		,width: 800
		,autoHeight: false
		,height: Ext.getBody().getViewSize().height*.95
		,autoScroll: true
		,labelAlign: 'top'
		,items: [{
            html: '<h2>' + _('wmg.boats.information') + '</h2>'
            ,border: false
            ,cls: 'modx-page-header'
        },{
			xtype: 'modx-tabs'
			,defaults: { border: false ,autoHeight: true }
			,border: true
			,items: this.getFields(config)
        }]
    });
    MODx.window.CreateBoatsData.superclass.constructor.call(this,config);
};

Ext.extend(MODx.window.CreateBoatsData,MODx.Window,{
    getFields: function(config) {
        var f = [{
            title: _('wmg.boats.tab_general')
            ,defaults: { autoHeight: true }
            ,cls: 'main-wrapper form-with-labels'
            ,items: this.getGeneralFields(config)
        },{
            title: _('wmg.boats.tab_facilities')
            ,defaults: { autoHeight: true }
            ,cls: 'main-wrapper form-with-labels'
            ,items: this.getFacilitiesFields(config)
        },{
            title: _('wmg.boats.tab_tech_specifications')
            ,defaults: { autoHeight: true }
            ,cls: 'main-wrapper form-with-labels'
            ,items: this.getTechSpecificationsFields(config)
        }];
        return f;
    }

    ,getGeneralFields: function(config) {
        return [{
            layout: 'column'
			,border: false
			,defaults: {
				layout: 'form'
				,labelAlign: 'top'
				,anchor: '100%'
				,border: false
			}
            ,items: [{
				columnWidth: .5
				,items: [{
					fieldLabel: _('wmg.boats.header_boatName_en')
					,name: 'boatName_en'
					,xtype: 'textfield'
					,allowBlank: false
					,anchor: '100%'
				},{
					fieldLabel: _('wmg.boats.header_boatDescription_en')
					,name: 'boatDescription_en'
					,xtype: 'textarea'
					,allowBlank: false
					,anchor: '100%'
				}]
			},{
				columnWidth: .5
				,items: [{
					fieldLabel: _('wmg.boats.header_boatName_de')
					,name: 'boatName_de'
					,xtype: 'textfield'
					,anchor: '100%'
				},{
					fieldLabel: _('wmg.boats.header_boatDescription_de')
					,name: 'boatDescription_de'
					,xtype: 'textarea'
					,anchor: '100%'
				}]
			}]
        }];
    }
	,getFacilitiesFields: function(config) {
        return [{
            layout: 'column'
			,border: false
			,defaults: {
				layout: 'form'
				,labelAlign: 'top'
				,anchor: '100%'
				,border: false
			}
            ,items: [{
                columnWidth: .5
                ,items: [{
                    fieldLabel: _('wmg.boats.header_boatDescription_en')
					,name: 'boatDescription_en1'
					,xtype: 'textarea'
					,allowBlank: false
					,anchor: '100%'
                }]
            },{
                columnWidth: .5
                ,items: [{
                    fieldLabel: _('wmg.boats.header_boatDescription_de')
					,name: 'boatDescription_de1'
					,xtype: 'textarea'
					,anchor: '100%'
                }]
            }]
        }];
    }
	,getTechSpecificationsFields: function(config) {
        return [{
            layout: 'column'
			,border: false
			,defaults: {
				layout: 'form'
				,labelAlign: 'top'
				,anchor: '100%'
				,border: false
			}
            ,items: [{
                columnWidth: .5
                ,items: [{
                    fieldLabel: _('wmg.boats.header_boatDescription_en')
					,name: 'boatDescription_en2'
					,xtype: 'textarea'
					,allowBlank: false
					,anchor: '100%'
                }]
            },{
                columnWidth: .5
                ,items: [{
                    fieldLabel: _('wmg.boats.header_boatDescription_de')
					,name: 'boatDescription_de2'
					,xtype: 'textarea'
					,anchor: '100%'
                }]
            }]
        }];
    }
});
Ext.reg('modx-window-boats-create',MODx.window.CreateBoatsData);

$modx->error->failure

public function beforeSave() {
        $name = $this->getProperty('name');
        $description= $this->getProperty('description');


        if (empty($name)) { // checks if field is empty
            $this->addFieldError('name',$this->modx->lexicon('yourcomponent.boat_err_ns_name'));
        } else if ($this->doesAlreadyExist(array('name' => $name))) { // checks if a duplicate of this entry already exists
            $this->addFieldError('name',$this->modx->lexicon('yourcomponent.boat_err_ae_name'));
        }

        if (empty($description)) { // checks if field is empty
            $this->addFieldError('description',$this->modx->lexicon('yourcomponent.boat_err_ns_description'));
        }
        return parent::beforeSave();
    }