If I use Mantis with german language and I choose within the user manage page the NEW (NEU) or UNUSED (UNBENUTZT) Filter button a wrong SQL is generated:

SELECT * FROM mantis_user_table WHERE (username like 'UNBENUTZT%') ORDER BY username ASC

SELECT * FROM mantis_user_table WHERE (username like 'NEU%') ORDER BY username ASC

SQL script for unused with english language:
SELECT * FROM mantis_user_table WHERE (login_count = 0) AND ( date_created = last_visit ) ORDER BY username ASC