Spring 3 - How to configure sessions persistence properly?

I have session persistence configured in Jetty. Simple example with Spring Security and jsp page works fine. Session is restored after server restart, I'm still authenticated. But after using EntityManager and some Spring components I get an axception on startup :

java.lang.IllegalStateException: Cannot deserialize BeanFactory with id org.springframework.web.context.WebApplicationContext:/MyApp: no factory registered for this id
    at org.springframework.beans.factory.support.DefaultListableBeanFactory$SerializedBeanFactoryReference.readResolve(DefaultListableBeanFactory.java:955)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at java.io.ObjectStreamClass.invokeReadResolve(ObjectStreamClass.java:1061)
    at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1762)
    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1329)
    at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:1947)
    at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1871)
    at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1753)
    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1329)
    at java.io.ObjectInputStream.defaultReadFie开发者_开发知识库lds(ObjectInputStream.java:1947)
    at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1871)
    at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1753)
    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1329)
    at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:1947)
    at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1871)
    at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1753)
    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1329)
    at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:1947)
    at java.io.ObjectInputStream.defaultReadObject(ObjectInputStream.java:480)
    at org.springframework.orm.jpa.SharedEntityManagerCreator$SharedEntityManagerInvocationHandler.readObject(SharedEntityManagerCreator.java:267)

Looks like EntityManager related problem. The :

 2010-06-25 09:35:55.906:INFO:/MyApp:Initializing Spring root WebApplicationContext null null

is just after the exception