NotSerializableException in org.jivesoftware.smack.filter.OrFilter

Hi

I am using JBoss server and its running in clustered mode and while running the application its throwing NotSerializableException in org.jivesoftware.smack.filter.OrFilter class, because this class is not impementing Serializable interface.The stack trace is as follows

java.io.NotSerializableException: org.jivesoftware.smack.filter.OrFilter
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1075)
at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1369)
at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1341)
at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1284)
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1073)
at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:291)
at java.util.Hashtable.writeObject(Hashtable.java:813)
at sun.reflect.GeneratedMethodAccessor20.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.ja va:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:890)
at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1333)
at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1284)
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1073)
at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:291)
at org.jboss.web.tomcat.tc5.session.SessionBasedClusteredSession.writeExternal(Ses sionBasedC
lusteredSession.java:175)

can any one suggest how to solve this problem???

Thanks