I faced the same problem with JBOSS. It's like JCE cannot acces to the .jar inside the war to validate it.
To solve the problem I added it to JAVA_HOME\jre\lib\ext and this way JCE can access and validate it without problems. You must keep including the .jar inside your war because, if not, JBOSS cannot find the classes (yes, it is silly: it can validate the jar frome jre\lib\ext but not load the classes from this location so you need to include it in your war)