Почему пропадает значение в combobox?

Practice.combo.Repository = function (config) {
    config = config || {};
    Ext.applyIf(config, {
        name: 'subject',
        fieldLabel: _('practice_item_subject'),
        hiddenName: 'subject',
        displayField: 'name',
        valueField: 'id',
        anchor: '99%',
	    preventRender: true,
        fields: ['name', 'id'],
        pageSize: 100,
        url: Practice.config.connector_url,
        //emptyText: _('no'),
        baseParams: {
            action: 'mgr/settings/getlist',
	        combo: true,
        }
    });
    Practice.combo.Repository.superclass.constructor.call(this, config);
};
Ext.extend(Practice.combo.Repository, MODx.combo.ComboBox);
Ext.reg('practice-combo',Practice.combo.Repository);

{
                xtype: 'practice-combo',
                fieldLabel: _('practice_item_subject'),
                anchor: '99%',
                allowBlank: true
            },

class SubjectItemGetListProcessor extends modObjectGetListProcessor
{
    public $objectType = 'SubjectItem';
    public $classKey = 'SubjectItem';
    public $defaultSortField = 'name';
    public $defaultSortDirection = 'ASC';
    //public $permission = 'list';


    /**
     * We do a special check of permissions
     * because our objects is not an instances of modAccessibleObject
     *
     * @return boolean|string
     */
    public function beforeQuery()
    {
        if (!$this->checkPermissions()) {
            return $this->modx->lexicon('access_denied');
        }

        return true;
    }


    /**
     * @param xPDOQuery $c
     *
     * @return xPDOQuery
     */
    public function prepareQueryBeforeCount(xPDOQuery $c)
    {
        $query = trim($this->getProperty('query'));

        if ($query) {
            $c->select(array('id','name'));
            $c->where(array(
                'name:LIKE' => "%{$query}%",
                //'OR:description:LIKE' => "%{$query}%",
            ));
        }

        return $c;
    }


    /**
     * @param xPDOObject $object
     *
     * @return array
     */
    public function prepareRow(xPDOObject $object)
    {
        $array = $object->toArray();
        $array['actions'] = array();

        // Edit
        $array['actions'][] = array(
            'cls' => '',
            'icon' => 'icon icon-edit',
            'title' => $this->modx->lexicon('subject_item_update'),
            //'multiple' => $this->modx->lexicon('subject_items_update'),
            'action' => 'updateItem',
            'button' => true,
            'menu' => true,
        );

        if (!$array['active']) {
            $array['actions'][] = array(
                'cls' => '',
                'icon' => 'icon icon-power-off action-green',
                'title' => $this->modx->lexicon('subject_item_enable'),
                'multiple' => $this->modx->lexicon('subject_items_enable'),
                'action' => 'enableItem',
                'button' => true,
                'menu' => true,
            );
        } else {
            $array['actions'][] = array(
                'cls' => '',
                'icon' => 'icon icon-power-off action-gray',
                'title' => $this->modx->lexicon('subject_item_disable'),
                'multiple' => $this->modx->lexicon('subject_items_disable'),
                'action' => 'disableItem',
                'button' => true,
                'menu' => true,
            );
        }

        // Remove
        $array['actions'][] = array(
            'cls' => '',
            'icon' => 'icon icon-trash-o action-red',
            'title' => $this->modx->lexicon('subject_item_remove'),
            'multiple' => $this->modx->lexicon('subject_items_remove'),
            'action' => 'removeItem',
            'button' => true,
            'menu' => true,
        );

        return $array;
    }

}

return 'SubjectItemGetListProcessor';