Not that we use ldap here (yet!), but I was reading through the changes 
and see that one of the bugs listed as fixed is:

   * the "port" option in the /etc/ldap.conf configuration file on client
     machines was ignored. For example, if a directory server which you
     were attempting to use was listening on a non-default port (i.e. not
     ports 389 or 636), it was only possible to use that directory server
     by including the port number in the "uri" option. In this updated
     package, the "port" option works as expected.

so if anyone had a port line before the update it was being ignored and it 
would use the default ones (as appropriate) but after the update it would 
be used even if it was incorrect e.g. using 389 not 636.

Of course it may be totally unrelated...

  -- Jon