BTW, I'm not using the class that appears in the call traceback: org.apache.axis...
I'm using com.sun.xml.messaging.saaj.soap.MessageFactoryImpl, javax.xml.soap.SOAPConnectionFactory and javax.xml.soap.SOAPConnection.
I tried adding the jars to the WEB-INF/lib dir with no success.
The problem was I was using Sun SOAP classes, which apparently JBoss/Tomcat don't like (BTW, I tried putting the jar files in the lib/endorsed directory, and it started to get better, but when I added the Sun's common-logging jar, JBoss web server couldn't start any more. Talk about write once, run anywhere.
I rewrote the code for Axis and it works, at least in JBoss 4.0.0 under Windows. It doesn't work in jboss-4.0.1sp1 under linux. Subject for another thread.