It looks like JMX monitoring doesn't work for MBeans with attributes which names contain dots.

For example attribute "jrockit.gc.pool.heap.used" - full Item key string "jmx["oracle.jrockit.management:type=PerfCounters","jrockit.gc.pool.heap.used"])".

Please see attached screenshot which illustrates the situation.

Issue looks like a major because the most important counters for jrockit contain dots.