Problem with multibyte encoding and locale support

Hello, all!

I want to configure postgresql as server with encoding on the fly (Postgres
7.0.2). I have few databases with KOI8 encoding and few ones with WIN
encoding. I ran ./configure --enable-locale --enable-multibyte=KOI8, made
and installed it. Then I ran initdb -E KOI8 and loaded my databases with
proper encoding in createdb.
Case 1. When I tried to connect db
$psql news
=# \encoding KOI8
=# select * from subscriber order by last;
I had got correct result. (DB news have KOI8 encoding).

Case 2. I tried to connect another db isrts with WIN encoding.
=# \c isrts
=# \encoding KOI8
=# select * from istor order by manager;
I had got WRONG result. (DB isrts have WIN encoding) The sort order was
wrong.

I recompiled postgresql server ./configure --enable-multibyte=KOI8 and tried
same commands.
In first case (db news with KOI8 encoding) I had WRONG result. The sort
order was wrong again.
In the second case (db isrts with WIN encoding) I had CORRECT result.

What does it mean? What did I do wrong?
Any help would be appricated.
Thanks.

Good Luck, Natalya Pyalling.

P.S. Please, reply to mak@rtsoft.msk.ru.