Well, found the problem.
Maybe it's stated somewhere, however, use of uri lists is broken with TLS but works with SSL.
If TLS is used the call of ldap_pvt_thread_mutex_lock() in back-ldap/bind.c:1584 comes never back and the server hangs.
OK, I see the problem. Please file an ITS for this issue: http://www.openldap.org/its/.
p.