I have the same problem. I could not even get the war/WEB-INF/MANIFEST.MF class-path entries to find the jars in the parent EAR.
The WIKI suggest this is suppose to work, however I have had no luck at all. http://wiki.jboss.org/wiki/Wiki.jsp?page=ClassLoadingConfiguration. After ensuring the suggested service configuration for isolated classloader is correct, still no luck with it. If you solved the problem I would be interested in what you did.
I have tried 4.0.2, and 4.0.3RC1 with the same results.
Try to put other .jar files in the jar file with deployment descriptor. Structure must be
foo(dir with you classes)
Tested on 4.0.2 & 4.0.3RC1. If you need isolation then read jboss wiki.
i put all .jar files in an explored directory with suffex .jar
and add the explored directory name as java module in application.xml .it can work well!
test on 4.0.2