Under load getting java.util.ConcurrentModificationException on SLSB create on 4.0.1sp1 at client, here is exception:

java.util.ConcurrentModificationException
at java.util.ArrayList.writeObject(ArrayList.java:573)
at sun.reflect.GeneratedMethodAccessor74.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java: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.invocation.jrmp.interfaces.JRMPInvokerProxyHA.writeExternal(JRMPInvokerProxyHA.java:303)
at java.io.ObjectOutputStream.writeExternalData(ObjectOutputStream.java:1304)
at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1282)
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1073)
at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:291)
at java.util.HashMap.writeObject(HashMap.java:985)
at sun.reflect.GeneratedMethodAccessor61.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java: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.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 org.jboss.proxy.ClientContainer.writeExternal(ClientContainer.java:138)
at java.io.ObjectOutputStream.writeExternalData(ObjectOutputStream.java:1304)
at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1282)
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1073)
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.HashMap.writeObject(HashMap.java:985)
at sun.reflect.GeneratedMethodAccessor61.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java: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.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 org.jboss.proxy.ClientContainer.writeExternal(ClientContainer.java:138)
at java.io.ObjectOutputStream.writeExternalData(ObjectOutputStream.java:1304)
at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1282)
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1073)
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.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.rmi.MarshalledObject.(MarshalledObject.java:92)
at org.jboss.invocation.jrmp.server.JRMPInvokerHA.invoke(JRMPInvokerHA.java:177)
at sun.reflect.GeneratedMethodAccessor92.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:294)
at sun.rmi.transport.Transport$1.run(Transport.java:153)
at java.security.AccessController.doPrivileged(Native Method)
at sun.rmi.transport.Transport.serviceCall(Transport.java:149)
at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:460)
at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:701)
at java.lang.Thread.run(Thread.java:595)
at sun.rmi.transport.StreamRemoteCall.exceptionReceivedFromServer(StreamRemoteCall.java:247)
at sun.rmi.transport.StreamRemoteCall.executeCall(StreamRemoteCall.java:223)
at sun.rmi.server.UnicastRef.invoke(UnicastRef.java:126)
at org.jboss.invocation.jrmp.server.JRMPInvoker_Stub.invoke(Unknown Source)
at org.jboss.invocation.jrmp.interfaces.JRMPInvokerProxyHA.invoke(JRMPInvokerProxyHA.java:173)
at org.jboss.invocation.InvokerInterceptor.invokeInvoker(InvokerInterceptor.java:163)
at org.jboss.invocation.InvokerInterceptor.invoke(InvokerInterceptor.java:103)
at org.jboss.proxy.TransactionInterceptor.invoke(TransactionInterceptor.java:46)
at org.jboss.proxy.SecurityInterceptor.invoke(SecurityInterceptor.java:55)
at org.jboss.proxy.ejb.HomeInterceptor.invoke(HomeInterceptor.java:169)
at org.jboss.proxy.ClientContainer.invoke(ClientContainer.java:91)
at $Proxy14.create(Unknown Source)