aplicação Jsf estourando pilha de java.util.ConcurrentModificationException

Boa tarde

Tenho uma aplicação com JSF 2 + primefaces + EJB + JPA,

Em alguns momentos que eu to navegando em minhas páginas aparece no console do glasfish a seguinte pilha:


Informações: Exception when handling error trying to reset the response.
java.util.ConcurrentModificationException
	at java.util.HashMap$HashIterator.nextEntry(HashMap.java:793)
	at java.util.HashMap$EntryIterator.next(HashMap.java:834)
	at java.util.HashMap$EntryIterator.next(HashMap.java:832)
	at org.jboss.weld.context.AbstractConversationContext.deactivate(AbstractConversationContext.java:250)
	at org.jboss.weld.jsf.WeldPhaseListener.deactivateConversations(WeldPhaseListener.java:131)
	at org.jboss.weld.jsf.WeldPhaseListener.afterPhase(WeldPhaseListener.java:92)
	at com.sun.faces.lifecycle.Phase.handleAfterPhase(Phase.java:189)
	at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:107)
	at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:139)
	at javax.faces.webapp.FacesServlet.service(FacesServlet.java:410)
	at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1534)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:281)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
	at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:655)
	at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:595)
	at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:98)
	at com.sun.enterprise.web.PESessionLockingStandardPipeline.invoke(PESessionLockingStandardPipeline.java:91)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:162)
	at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:326)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:227)
	at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:170)
	at com.sun.grizzly.http.ProcessorTask.invokeAdapter(ProcessorTask.java:822)
	at com.sun.grizzly.http.ProcessorTask.doProcess(ProcessorTask.java:719)
	at com.sun.grizzly.http.ProcessorTask.process(ProcessorTask.java:1013)
	at com.sun.grizzly.http.DefaultProtocolFilter.execute(DefaultProtocolFilter.java:225)
	at com.sun.grizzly.DefaultProtocolChain.executeProtocolFilter(DefaultProtocolChain.java:137)
	at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:104)
	at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:90)
	at com.sun.grizzly.http.HttpProtocolChain.execute(HttpProtocolChain.java:79)
	at com.sun.grizzly.ProtocolChainContextTask.doCall(ProtocolChainContextTask.java:54)
	at com.sun.grizzly.SelectionKeyContextTask.call(SelectionKeyContextTask.java:59)
	at com.sun.grizzly.ContextTask.run(ContextTask.java:71)
	at com.sun.grizzly.util.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:532)
	at com.sun.grizzly.util.AbstractThreadPool$Worker.run(AbstractThreadPool.java:513)
	at java.lang.Thread.run(Thread.java:619)

Advertência: StandardWrapperValve[Faces Servlet]: PWC1406: Servlet.service() for servlet Faces Servlet threw exception
java.util.ConcurrentModificationException
	at java.util.HashMap$HashIterator.nextEntry(HashMap.java:793)
	at java.util.HashMap$EntryIterator.next(HashMap.java:834)
	at java.util.HashMap$EntryIterator.next(HashMap.java:832)
	at org.jboss.weld.context.AbstractConversationContext.deactivate(AbstractConversationContext.java:250)
	at org.jboss.weld.jsf.WeldPhaseListener.deactivateConversations(WeldPhaseListener.java:131)
	at org.jboss.weld.jsf.WeldPhaseListener.afterPhase(WeldPhaseListener.java:92)
	at com.sun.faces.lifecycle.Phase.handleAfterPhase(Phase.java:189)
	at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:107)
	at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:139)
	at javax.faces.webapp.FacesServlet.service(FacesServlet.java:410)
	at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1534)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:281)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
	at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:655)
	at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:595)
	at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:98)
	at com.sun.enterprise.web.PESessionLockingStandardPipeline.invoke(PESessionLockingStandardPipeline.java:91)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:162)
	at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:326)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:227)
	at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:170)
	at com.sun.grizzly.http.ProcessorTask.invokeAdapter(ProcessorTask.java:822)
	at com.sun.grizzly.http.ProcessorTask.doProcess(ProcessorTask.java:719)
	at com.sun.grizzly.http.ProcessorTask.process(ProcessorTask.java:1013)
	at com.sun.grizzly.http.DefaultProtocolFilter.execute(DefaultProtocolFilter.java:225)
	at com.sun.grizzly.DefaultProtocolChain.executeProtocolFilter(DefaultProtocolChain.java:137)
	at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:104)
	at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:90)
	at com.sun.grizzly.http.HttpProtocolChain.execute(HttpProtocolChain.java:79)
	at com.sun.grizzly.ProtocolChainContextTask.doCall(ProtocolChainContextTask.java:54)
	at com.sun.grizzly.SelectionKeyContextTask.call(SelectionKeyContextTask.java:59)
	at com.sun.grizzly.ContextTask.run(ContextTask.java:71)
	at com.sun.grizzly.util.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:532)
	at com.sun.grizzly.util.AbstractThreadPool$Worker.run(AbstractThreadPool.java:513)
	at java.lang.Thread.run(Thread.java:619)

Alguém tem idéia do que poderia ser?