This does not work here.
I added seam3 reports (and jasperreports) into myapplication, and excluded dom4j in pom.
Either I added dom4j in jboss-deployment-structure.xml or war plugin configuration, the same problem occured.
maven-war-plugin
<archive>
<manifestEntries>
<Dependencies>org.dom4j</Dependencies>
</manifestEntries>
</archive>
jboss-deployment-structure.xml
<jboss-deployment-structure>
<deployment>
<dependencies>
<module name="org.jboss.logmanager" />
<module name="org.dom4j" />
</dependencies>
</deployment>
</jboss-deployment-structure>