Btw the exception above is due to a load-on-startup tag inside the web.xml. Jboss does not like the give priority; removing this tag the deploy runs fine. It maybe caused by several servlet loaded by Struts and Birt together in the same application. If you don't have special needs, best practice is to not specify load-on-startup, leaving the loading order to the servlet container. Hope I'm right.
Thanks for your help.
Simon