Hi, we have had this working on Magento 1.9 for about a year, then suddenly noticed its not working anymore.

Inserted die(); line 46 app\code\community\Activo\CatalogSearch\Model\Mysq l4\fulltext.php

Search still loads (cleared cache, saved search)

Shows correctly in System > Config > Advanced > Advanced

Have Magento search set to Like & have no other search extensions