Problem with encoding (lower() doesn't work)

[Vitaliyi <imgrey@xxxxxxxxx>]

Steps :
export LANG=ru_RU.KOI8-r (locale was set properly)
initdb
createdb -E WIN tst
psql tst < tsearch2.sql
 psql tst :
 SET client_encoding to KOI8;
 create table tst (name text, v tsvector);
 insert ..
 update tst set v = to_tsvector(lower(nm));

and i've got capitalized russian text in v (vectors) :(

the select * from lower(); isnt working too

I've tried Postgres 8.1 and 8.2