Ejb Stateful Could not activate; failed to restore state

[hibernator_11]

Hi all,

I am using an Ejb stateful in my web but after ten minutes i got the exception Could not activate; failed to restore state.

this code is in my servlet:

HttpSession session = request.getSession(true);

UnidadDocumentalBoEjbLocal ejbud = (BoEjbLocal) session.getAttribute("ejbud");

if(ejbud == null)

{

      //get the default JNDI initial context

      Context ctx = new InitialContext();

      //get the bussiness interface

      Object obj = ctx.lookup("jbib-enterprise/BoEjb/local");

      //convert obj

       ejbud = (BoEjbLocal) obj;

       session.setAttribute("ejbud", ejbud);

}

Before the exception i can see in my log:

(SFSB Passivation Thread - jboss.j2ee:ear=jbib-enterprise.ear,....) passivate

In my standardjboss.xml i have:

	<max-bean-life>1800</max-bean-life>
	<overager-period>300</overager-period>
	<!-- <max-bean-age>600</max-bean-age> -->
	<max-bean-age>1800</max-bean-age>

i see that in my folder tmp/log of my server is the session file....

how can i reactivate my session after passivating ???

thanks in advance.

[hibernator_11]

First i get javax.ejb.EJBException: Could not passivate; failed to save state

i don't know what can i do....

maybe i have to set up to null all my properties in my stateful session because in other case they can not be serializated...