I just noticed that, in a fit of housekeeping, it looks I changed ServerThread from version 2.2 to 2.4 so that, instead of calling getClass.getClassLoader() with each invocation, it creates private static ClassLoader classLoader = SecurityUtility.getClassLoader(ServerThread.class); Should I write a 1000 times "DO NOT CREATE STATIC REFERENCES TO CLASSLOADERS"? If you make it an instance variable, does the problem go away? I'd try it but I screwed up my copy of AS 5.0.0.CR2 and I'm still downloading a clean copy from SVN. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4175779#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...