Combination of Searchable and I18n behaviors

Screencast:
  tableName: screencast
  actAs:
    Timestampable: ~
    I18n:
      fields:
        - title
        - is_sub_visible
      actAs:
        Searchable:
          fields: [title]
  columns:
    id:
      type: integer
      primary: true
      autoincrement: true
      unsigned: true
    slug: { type: string(127), notnull: true }
    is_visible: boolean(false)
    title: string(255)
    is_sub_visible: boolean(false)
  indexes:
    is_visible: { fields: [is_visible] }
    slug: { fields: [slug], type: unique }

<?php

// initializing Screencast and ScreencastTranslation tables
// in other case, will be thrown Doctrine_Exception with message "Couldn't find class ScreencastTranslation"
ScreencastTable::getTable();


$i18nTable = Doctrine::getTable('ScreencastTranslation');

// create query instance and add filter by "is_sub_visible = true" column
$q = $i18nTable->createQuery('st')->addWhere('st.is_sub_visible = ?', true);

// run search query
$q = $i18nTable->search('doctrine', $q);

// prints:
// FROM ScreencastTranslation st WHERE st.is_sub_visible = ? AND st.id IN (SQL:SELECT id FROM screencast_translation_index WHERE keyword = ? GROUP BY id)
print $q->getDql();

$doctrineCollection = $q->execute(); // on this line throws Doctrine_Hydrator_Exception

?>