Encoding problems

Hello,
I have a problem when trying to insert data with accents (é,è,à,ç ...)
or arabic/chinese caracters.

here's a snapshot :

[root(at)apps applications]# psql -Ueserve -W -deserve -f output.sql
Mot de passe :
psql:output.sql:1: ERREUR: Séquence d'octets invalide pour le codage
«UNICODE» : 0xe96469

here's what output.sql contain :
INSERT INTO sms_mo("MsgId","DA","SOA","Content","Msg","TimeCreated")
VALUES('3','216123456','33437376969','Le crédit d','Le crédit de votre
compte est bas : charger.','Oct 27 2004 5:00PM');

when replacing the 'é' with 'e' it works fine...
how to do to setup postgresql server to accept this kind of charset ?