One way to deal with the 1% case might be to give each ref a transient sequence number as they are added to the queue, that represents their position in the queue. If the iterator.next() goes dead because the ref has been removed while iterating, then you can go back the beginning of the queue and traverse it one by one until you get to an element where sequence number > last sequence number seen. Just a thought. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4181502#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...