Hi,
you're not supposed to change the ws stack on JBoss EAP. I *think* the exception you get is basically due to an improper installation of the 3.3.0 stack. The supported target container list shown at http://community.jboss.org/wiki/JBossWS-SupportedTargetContainers refers to the community JBoss AS. JBossWS 3.3.0 installation has not been tested with EAP 5.0, but with JBoss AS 5.1.0.GA; just comment here below if you see the same issue with that and we'll try to reproduce and look at it.
In case you need some specific feature of 3.3.0 on EAP5.x, please get in touch with your JBoss product contact.
Thanks