An exception in the satelite log w.r.t events

in the satelite log file , i encountered this error , can anybody help me out in fixing this issue.

[Thread : Thread-80] ERROR2007-01-17 14:16:30.52 ISTSummarizing events
[Thread : Thread-80] ======== Begin StackTrace ======
java.lang.ClassCastException: com.dante.util.Marker
at com.webmethods.optimize.event.agent.EventAgentLogic.summarize(EventAgentLogic.java:117)
at com.webmethods.optimize.event.agent.EventAgent.summarizeEvents(EventAgent.java:61)
at sun.reflect.GeneratedMethodAccessor9.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:324)
at com.sun.jdmk.MBeanServerImpl.invoke(MBeanServerImpl.java:1624)
at com.sun.jdmk.MBeanServerImpl.invoke(MBeanServerImpl.java:1519)
at com.webmethods.optimize.mobile.agent.eventmessenger.EventMessenger.pollAgents(EventMessenger.java:67)
at com.webmethods.optimize.mobile.agent.eventmessenger.EventMessenger.access$000(EventMessenger.java:29)
at com.webmethods.optimize.mobile.agent.eventmessenger.EventMessenger$1.run(EventMessenger.java:49)
at java.util.TimerThread.mainLoop(Timer.java:432)
at java.util.TimerThread.run(Timer.java:382)