What if you put the relevant JMX libs from JBoss into the *ext* directory or the JDK ? Maybe that helps ... ?
I'll try that out, in the meantime - I just unjar'd the xmlc.jar package, unsealed it, then stuck in back in the AppServer/lib directory..
In anothe rnote, I start up the TreeCache via a CustomService (similar to the weblogic example) - the only problem is one can't bind it to JNDI (WebSphere only allows Serializable Objects to be bound). Instead, I had to go with a singleton approach. I was wondering how others did it..