SASL problem

[Robert Szentmihalyi]

I have an authentication problem for SOME users when connecting to their
mailboxes.
I guess it might be related to this:
Jul 21 15:05:13 m2 saslauthd[15834]: ipc_init        : listening on
socket: /var/lib/sasl2/mux
Jul 21 15:05:13 m2 kolabd[15871]: Kolab is starting up
Jul 21 15:05:13 m2 master[15874]: about to exec /usr/lib/cyrus/imapd
Jul 21 15:05:13 m2 imap[15874]: executed
Jul 21 15:05:13 m2 imap[15874]: auxpropfunc error invalid parameter supplied
Jul 21 15:05:13 m2 imap[15874]: _sasl_plugin_load failed on
sasl_auxprop_plug_init for plugin: ldapdb
Jul 21 15:05:13 m2 imap[15874]: accepted connection
Jul 21 15:05:13 m2 saslauthd[15835]: Domain/Realm not available.
Jul 21 15:05:13 m2 saslauthd[15835]: Domain/Realm not available.
Jul 21 15:05:13 m2 imap[15874]: login: localhost [127.0.0.1] manager
plaintext User logged in
Jul 21 15:06:13 m2 master[5525]: process 15874 exited, status 0

Any ideas?

TIA,
 Robert