to_tsvector: error with italian configuration

Hi all, I was looking into PostgreSQL’s full-text search but when  
using the to_tsvector function with italian settings I get this error:
> test=> select to_tsvector('italian','prova');
> ERROR:  invalid byte sequence for encoding "UTF8": 0xc3
> HINT:  This error can also happen if the byte sequence does not  
> match the encoding expected by the server, which is controlled by  
> "client_encoding".

whereas using english works fine:

> test=> select to_tsvector('english','prova');
>  to_tsvector
> -------------
>  'prova':1
> (1 row)

Danish’s fine too, but not french (same error). All the .stop files  
(italian, french, and danish) are utf8-encoded but maybe it doesn’t  
matter, I just don’t know.

I’m using the 8.3 version with Mac OS X 10.5.3 (pg server) and Mac OS  
X 10.4.11 (psql client).


Thank you
--
Giorgio Valoti