[courier-users] courier-imap ldap authentification randomly failed

[Tuff]

Hi
I am running courier-imap with openldap and use Thunderbird imap client for testing issues. I need to login the same user ("intraadmin") to two different imap servers (with the same ldap server).
The authentification pocess often fails. Is it a normal behavior ? Is it possible to do so? if yes, How ?


here is the output log

Feb 22 09:46:00 server1 imapd: Connection, ip=[::ffff:127.0.0.1]
Feb 22 09:46:25 server1 authdaemond: received auth request, service=imap, authtype=login
Feb 22 09:46:25 server1 authdaemond: authldap: trying this module
Feb 22 09:46:25 server1 authdaemond: selected ldap protocol version 3
Feb 22 09:46:25 server1 authdaemond: binding to LDAP server as DN 'cn=Manager, dc=my_company, dc=com', password 'my_passwd'
Feb 22 09:46:40 server1 imapd: LOGIN FAILED, [EMAIL PROTECTED], ip=[::ffff:127.0.0.1]
Feb 22 09:46:40 server1 imapd: authentication error: Input/output error
Feb 22 09:46:40 server1 authdaemond: using search filter: (&(objectClass=qmailUser)([EMAIL PROTECTED]))
Feb 22 09:46:41 server1 authdaemond: one entry returned, DN: uid=intraadmin,ou=personnes,dc=my_company,dc=com
Feb 22 09:46:41 server1 authdaemond: raw ldap entry returned:
Feb 22 09:46:41 server1 authdaemond: | userPassword: {SHA}jdVZcpnXU3D0huvYifNXuxjHhxW=
Feb 22 09:46:41 server1 authdaemond: | mailMessageStore: /var/maildirs/intraadmin
Feb 22 09:46:41 server1 authdaemond: | mail: [EMAIL PROTECTED]
Feb 22 09:46:41 server1 authdaemond: | cn: Administrateur de l'Intranet
Feb 22 09:46:41 server1 authdaemond: authldaplib: sysusername=<null>, sysuserid=11184, sysgroupid=2110, homedir=/var/maildirs/intraadmin, [EMAIL PROTECTED], fullname=Administrateur de l'Intranet, maildir=<null>, quota=<null>, options=<null>
Feb 22 09:46:41 server1 authdaemond: authldaplib: clearpasswd=<null>, passwd={SHA}jdVZcpnXU3D0huvYifNXuxjHhxW=
Feb 22 09:46:41 server1 authdaemond: password matches successfully
Feb 22 09:46:41 server1 authdaemond: Authenticated: sysusername=<null>, sysuserid=11184, sysgroupid=2110, homedir=/var/maildirs/intraadmin, [EMAIL PROTECTED], fullname=Administrateur de l'Intranet, maildir=<null>, quota=<null>, options=<null>
Feb 22 09:46:41 server1 authdaemond: Authenticated: clearpasswd=a_passwd, passwd={SHA}jdVZcpnXU3D0huvYifNXuxjHhxW=
Feb 22 09:46:41 server1 authdaemond: authldap: TEMPFAIL - no more modules will be tried
Feb 22 09:46:46 server1 imapd: Connection, ip=[::ffff:127.0.0.1]