Thanks for the reply.
XML requires that any message ends with "\0" although other things may be accepted. Once 'listen' has accepted the incoming caller the connection is made and the rest doesn't matter. For the moment I am just trying to get the connection to be made with flash as it does with php. I've done a fair bit of this stuff but quite a few years ago and things have changed a bit so it's very frustrating to not be able to do it (apart from needing it urgently for a work project!)
Thanks again - doc