iChat Server WAN no dialback starting

HI

We are setting up a server for a small community and want to use the iChat server over WAN.

Going over and over again the setting and port issues we still can't figure out what is going wrong.

This is the log we get when somebody tries to log in to the server.

Nov 30 18:55:20 dataheerd1 jabberd/s2s[74938]: [7] [::ffff:xxx.yyy.186.222, port=49941] incoming connection

Nov 30 18:55:20 dataheerd1 jabberd/s2s[74938]: [] [::ffff:xxx.yyy.186.222, port=49941] incoming stream online (id 9fb4yrk9g8xricmo7nbz9jw38mdrwgn6g90qfhti)

connection seams to be allright (coming from ip xxx.yyy.186.222)

but then:

Nov 30 18:56:25 dataheerd1 jabberd/s2s[74938]: [7] [::ffff:xxx.yyy.186.222, port=49941] no dialback started

Nov 30 18:56:25 dataheerd1 jabberd/s2s[74938]: [7] [::ffff:xxx.yyy.186.222, port=49941] disconnect, packets: 1

Can anybody help us out?

All tips are welcome...

Regards