jBoss-5.0.1.GA, Seam-2.1.1.GA, Wicket-1.3.4.GA, JDK-6u12

Clustering a seam-wicket application works fine if:
1) I use WEB-INF/classes dir and instrument wicket classes
2) every server has received a request which load wicket component

I think the second point is an issue because this way I can't manage automatic server restart.

If server doesn't receive any request prior the real request I receive the following error:

12:37:26,872 ERROR CoyoteAdapter An exception or error occurred in the container during the request processing
java.lang.ExceptionInInitializerError
     at sun.misc.Unsafe.ensureClassInitialized(Native Method)
     at sun.reflect.UnsafeFieldAccessorFactory.newFieldAccessor(UnsafeFieldAccessorFactory.java:25)
     at sun.reflect.ReflectionFactory.newFieldAccessor(ReflectionFactory.java:122)
     at java.lang.reflect.Field.acquireFieldAccessor(Field.java:918)
     at java.lang.reflect.Field.getFieldAccessor(Field.java:899)
     at java.lang.reflect.Field.getLong(Field.java:528)
     at java.io.ObjectStreamClass.getDeclaredSUID(ObjectStreamClass.java:1614)
     at java.io.ObjectStreamClass.access$700(ObjectStreamClass.java:52)
     at java.io.ObjectStreamClass$2.run(ObjectStreamClass.java:425)
     at java.security.AccessController.doPrivileged(Native Method)
     at java.io.ObjectStreamClass.<init>(ObjectStreamClass.java:413)
     at java.io.ObjectStreamClass.lookup(ObjectStreamClass.java:310)
     at java.io.ObjectStreamClass.initNonProxy(ObjectStreamClass.java:547)
     at java.io.ObjectInputStream.readNonProxyDesc(ObjectInputStream.java:1583)
     at java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1496)
     at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1732)
     at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1329)
     at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:1947)
     at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1871)
     at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1753)
     at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1329)
     at java.io.ObjectInputStream.readObject(ObjectInputStream.java:351)
     at java.util.HashMap.readObject(HashMap.java:1030)
     at sun.reflect.GeneratedMethodAccessor293.invoke(Unknown Source)
     at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
     at java.lang.reflect.Method.invoke(Method.java:597)
     at java.io.ObjectStreamClass.invokeReadObject(ObjectStreamClass.java:974)
     at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1849)
     at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1753)
     at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1329)
     at java.io.ObjectInputStream.readObject(ObjectInputStream.java:351)
     at org.jboss.ha.framework.server.SimpleCachableMarshalledValue.get(SimpleCachableMarshalledValue.java:94)
     at org.jboss.web.tomcat.service.session.distributedcache.impl.jbc.AbstractJBossCacheService.getUnMarshalledValue(AbstractJBossCacheService.java:666)
     at org.jboss.web.tomcat.service.session.distributedcache.impl.jbc.SessionBasedJBossCacheService.getSessionAttributes(SessionBasedJBossCacheService.java:113)
     at org.jboss.web.tomcat.service.session.distributedcache.impl.jbc.AbstractJBossCacheService.getDistributableSessionData(AbstractJBossCacheService.java:587)
     at org.jboss.web.tomcat.service.session.distributedcache.impl.jbc.AbstractJBossCacheService.loadSession(AbstractJBossCacheService.java:372)
     at org.jboss.web.tomcat.service.session.JBossCacheManager.loadSession(JBossCacheManager.java:1524)
     at org.jboss.web.tomcat.service.session.JBossCacheManager.findSession(JBossCacheManager.java:462)
     at org.jboss.web.tomcat.service.session.ClusteredSessionValve.invoke(ClusteredSessionValve.java:104)
     at org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:92)
     at org.jboss.web.tomcat.security.SecurityContextEstablishmentValve.process(SecurityContextEstablishmentValve.java:126)
     at org.jboss.web.tomcat.security.SecurityContextEstablishmentValve.invoke(SecurityContextEstablishmentValve.java:70)
     at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
     at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
     at org.jboss.web.tomcat.service.jca.CachedConnectionValve.invoke(CachedConnectionValve.java:158)
     at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
     at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:330)
     at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:829)
     at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:601)
     at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
     at java.lang.Thread.run(Thread.java:619)
Caused by: java.lang.NullPointerException
     at org.jboss.seam.wicket.WicketComponent.<init>(WicketComponent.java:170)
     at cbi.wicket.CoreApplication.<clinit>(CoreApplication.java)
     ... 51 more