dovecot - Jul 2011 - National characters

Hi,

I upgrade my server an I have dovecot 2.0.9 (on RedHat 6) and my user 
uses Thunderbird 5.0 (on Windows XP).
I use authentication via LDAP (Windows server 2003 AD).

When users use in password diacritic marks (?,?,?,?,?,?) authentication 
failed.
For example when user test have password: Sierpie???*123 in log file 
item appears:
localhost dovecot: auth: ldap(test,192.168.0.68): invalid credentials 
(given password : SierpieDB#005*123)

What can I do?


Thanks