Hibernate托管的Object的ID在转发到新的ActionClass后被重置

I have a Struts 1.3 and Hibernate 3.1 application that uses an open-session-in-view pattern for maintaining hibernate transactions. After I do a session.save() on an object its identifier is being set in the object, however after I pass the object to a new action class all of the properties that are managed by hibernate, like the object's identifier are being set to null. I have a Struts 1.3 and Hibernate 3.1 applicati