Ferret and right to left languages support

I’ve successfully installed ferret and acts_as_ferret and have no
problem with utf-8 for accented characters. It returns correct results
fot e.g. français. My problem is with non latin characters (Persian
indeed). I have tested different locales with no success both on Debian
and Mac. Any idea?
(ferret 0.11.4, acts_as_ferret 0.4.0, rails 1.1.6)

mistaken title, I kindly ask the moderator to delete this topic.