Hi Brian, (First I apologize for spelling your name wrong the first time ;-)) You're absolutely right that this error only happens when setting the granularity to FIELD and the marshal flag true. Just checked it again with ATTRIBUTE and no errors what so ever. Must have overlooked the fact that this aspect worked, since the whole clustering doesn't work for me with other granularity than FIELD (but that's another story, won't bother you with that). Thanks for your help so far! Regards, Lau View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3993568#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...