Hi,
as far as I know, you need JBoss 6 to use JavaEE6 features like JSF 2.0 - so I would assume that it will not work with JBoss 5.1.
Actually, your error message sounds like a broken archive file, but I remember having read something somewhere that "broken" deployment descriptors might cause this error, too. So you might check whether all xml files in your archive are valid.
Best regards
Wolfgang