With no changes, I migrated a web app [myapp.war] from Jboss 3.2.3 where it works fine to 4.0.3SP1. First error occurred and deployment failed because <jsp-file> in declaration of web.xml did not begin with /. That seems to be resolved.
Now the app deploys and works fine except when the action is to post to a servlet. JSP files are accessed fine, as are bean classes in WEB-INF/classes. However, none of the servlets can be found, generated a Tomcat 404. I have verified the unpacked servlet class files are in the path specified in web.xml under WEB-INF/classes of unpacked war file (<jboss-home>/server/default/tmp/deploy/tmp63185myapp.war).
The exact same app works fine in 3.2.3, so obviously something has changed in 4.0.3, but I haven't yet figured out what. Please help.