I've changed in FAQ.module.php

Code:

      $query = "SELECT
                        entry_id, question, answer
                     FROM
                        " . cms_db_prefix() . "module_gbook_entries,
                     WHERE
                        active=1";


to

Code:

$query = "SELECT entry_id, question, answer FROM " . cms_db_prefix() .
"module_faq_entries WHERE active=1";


It was a wrong call to table module_gbook_entries and stray comma giving a SQL
error when reindexing in Search Module.