hi,
i have a problem when i run ex11_1

[java] Making a payment using byCash()..
[java] Making a payment using byCheck()..
[java] Making a payment using byCredit()..
[java] Making a payment using byCheck() with a low check number..
[java] java.lang.reflect.UndeclaredThrowableException
[java] at $Proxy1.byCheck(Unknown Source)
[java] at com.titan.clients.MakePayment.main(MakePayment.java:56)
[java] Caused by: java.lang.ClassNotFoundException: [Ljava.lang.StackTraceElement;
[java] at java.net.URLClassLoader$1.run(Unknown Source)
[java] at java.security.AccessController.doPrivileged(Native Method)
[java] at java.net.URLClassLoader.findClass(Unknown Source)
[java] at java.lang.ClassLoader.loadClass(Unknown Source)
[java] at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
[java] at java.lang.ClassLoader.loadClass(Unknown Source)
[java] at org.jboss.remoting.loading.RemotingClassLoader.loadClass(RemotingClassLoader.java:50)
[java] at org.jboss.remoting.loading.ObjectInputStreamWithClassLoader.resolveClass(ObjectInputStreamWithClassLoader.java:139)
[java] at java.io.ObjectInputStream.readNonProxyDesc(Unknown Source)
[java] at java.io.ObjectInputStream.readClassDesc(Unknown Source)
[java] at java.io.ObjectInputStream.readArray(Unknown Source)
[java] at java.io.ObjectInputStream.readObject0(Unknown Source)
[java] at java.io.ObjectInputStream.defaultReadFields(Unknown Source)
[java] at java.io.ObjectInputStream.readSerialData(Unknown Source)
[java] at java.io.ObjectInputStream.readOrdinaryObject(Unknown Source)
[java] at java.io.ObjectInputStream.readObject0(Unknown Source)
[java] at java.io.ObjectInputStream.defaultReadFields(Unknown Source)
[java] at java.io.ObjectInputStream.readSerialData(Unknown Source)
[java] at java.io.ObjectInputStream.readOrdinaryObject(Unknown Source)
[java] at java.io.ObjectInputStream.readObject0(Unknown Source)
[java] at java.io.ObjectInputStream.readObject(Unknown Source)
[java] at org.jboss.remoting.serialization.impl.java.JavaSerializationManager.receiveObject(JavaSerializationManager.java:128)
[java] at org.jboss.remoting.marshal.serializable.SerializableUnMarshaller.read(SerializableUnMarshaller.java:66)
[java] at org.jboss.remoting.transport.socket.SocketClientInvoker.transport(SocketClientInvoker.java:279)
[java] at org.jboss.remoting.RemoteClientInvoker.invoke(RemoteClientInvoker.java:143)
[java] at org.jboss.remoting.Client.invoke(Client.java:525)
[java] at org.jboss.remoting.Client.invoke(Client.java:488)
[java] at org.jboss.aspects.remoting.InvokeRemoteInterceptor.invoke(InvokeRemoteInterceptor.java:55)
[java] at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
[java] at org.jboss.aspects.tx.ClientTxPropagationInterceptor.invoke(ClientTxPropagationInterceptor.java:61)
[java] at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
[java] at org.jboss.aspects.security.SecurityClientInterceptor.invoke(SecurityClientInterceptor.java:55)
[java] at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
[java] at org.jboss.ejb3.remoting.IsLocalInterceptor.invoke(IsLocalInterceptor.java:65)
[java] at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
[java] at org.jboss.ejb3.stateless.StatelessRemoteProxy.invoke(StatelessRemoteProxy.java:102)
[java] ... 2 more

anybody can help ?
thanks