Veronica
Try using two tx buffer decriptors rather than one (which I assume you presently have). My experience is that a frame in a single buffer description is always sent twice, which never happens when more than one buffer is available. You can also prepare the frame to be transmitted to be chained in 2 buffer descriptions (eg. IP part in first and UDP etc. part in second). which shoud stop it happening.
If you find another solution, please also let us know!!
Regards
Mark Butcher

Message Edited by mjbcswitzerland on 2007-02-0607:28 PM