I can't for the life of me find where to download java 1.6 (or 6.0) for mac. From everything I am looking at, it is still in beta. I would have to guess that the solution would be similar to my comment below (which is to delete the compibility jar file):
It appears that Apple decided to include old libraries like crimson and xalan, among others, with java 1.5. The only solution is to removed the old compatibility jars from the JDK. This seems like a bad solution to me, but this is also what Spring recommends in its FAQs. See http://static.springframework.org/spring-ws/site/faq.html.
It will be in: