[Dovecot] Messages does not appear in OE6

[Mauricio Araya V.]

Hi List!

I have an issue with dovecot: Outlook express users sometimes can't see
some emails (they are not even listed) that can be seen with other IMAP
clients, I tested it (and it works) with Evolution, Outlook and
SquirrelMail (a web mail).

Please note that this is not the client bug reported at
http://dovecot.org/clients.html  with the message: "Message is no longer
available on this server"

I have the following configuration:
- Postfix as MTA (ver. 2.1), using the Maildir format to store messages.
- Dovecot 0.99.10.4_2 serving POP3 and IMAP.

Relevant dovecot config:
client_workarounds = oe6-fetch-no-newmail outlook-idle
default_mail_env = maildir:/%h/Maildir

Something important is that I am using freebsd 4.9, and dovecot is
installed from ports (/usr/ports/mail/dovecot)

Does anyone has the solution for this problem, or at least an idea of
what causes it?

Regards,
-Mauricio