Hi Francisco Sucena,
I have the same problem in the soap api that I have consumed, for me xmlns is add in request. Because of it I'm receiving the exception after hitting it as "BIP3113E: Exception detected in message flow servername.modulename.enq.ServiceGatway.SOAP Input (integration node nodename) "
Did you got any workaround in your case without using SOAP Extensibility API. Please let me know.
Regards,
Arun Kumar