The problem you're having with JBoss 4.x is that they changed the method of implementing "interceptors". I take it you couldn't find the file called "jacorb.properties" to change it according to the install manual to include the part about "org.omg.PortableInterceptor...". I had the same problem, was never able to find a way to get it to work with the new XML-based dynamic interceptors, and reverted to JBoss 3.2.5.
However, I'm having an issue similar to yours with credential permissions in JBoss 3.2.5. Take a look at your server.log file (located under [jboss]/server/all/log/). If you backtrack from the end until you find the original error, it probably stems from the PDFManipulator, and says your alias could not be found. I'm trying to fix that on my own installation at the moment, probably something obvious I just happen to be overlooking a dozen times.