Because I suspect the jdk1.5 javax.management.timer.Timer implementation uses a java.util.Timer which creates a single thread to execute schedules, and this can screw up your timing if executing a task takes time. The jboss javax.management.timer.Timer (if you use jdk14) has a nice and dynamically extensible thread pool to do the same thing, and so it scales a lot better. Xaireto View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4000775#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...