[Dovecot] Password and special caracter

Problem : I have a problem with special character in the password. Character like ! * é are deleted

My configuration :

• a smtp server with Postfix 2.6 and Dovcot 1.1.11.
• a windows 2003 server with active directory for accounts and boxes

I use SMTP / SASL on my postfix 2.6 to authenticate my remote laptop users (allow legitimate users to relay mail).

To do that, I use SASL Dovecot fonctionnality and ldap request to verify login/password who are declared on a server in Windows 2003 (Active Directory).

It works fine with simple password but not with complex password. I have a problem with special character in the password. Character like ! * é are deleted before comparaison.

Any idea ?

Regards