Fedora directory users - Mar 2006 - fds and sendamil on solaris9

hi
i use fds on solaris 9 as users database
i can send , receive email , alias works
but i have a few mail that seems to be sent but i never receive
and here are logs i can see just after sendmail receive the mail :

Mar  8 16:32:39 mailer sm-mta[874]: [ID 801593 mail.info] 
k28FWdpb000874: from=<toto@siris.sorbonne.fr>, size=375, class=0, 
nrcpts=1, msgid=<440EF916.30503@siris.sorbonne.fr>, proto=ESMTP, 
daemon=Daemon0,
relay=pc.sorbonne.fr [xxx.xxx.xxx.xxx]
Mar  8 16:32:39 mailer sm-mta[878]: [ID 293258 mail.error] libsldap: 
Status: 91  Mesg: Error 0
Mar  8 16:32:39 mailer last message repeated 1 time
Mar  8 16:32:39 mailer sm-mta[878]: [ID 293258 mail.error] libsldap: 
Status: 7  Mesg: Session error no available conn.

thanks
basile