I've been using Hibernate all through the development of a very simple application, until now all my entities are modified, added and deleted without a problem using Hibernate mapping.

The problem arose now when using it with a derived class. I used the per-subclass approach when mapping inheritance; I have Person class and Employee derives from it.

When deleting an Employee item, I get a "illegally attempted to associate a proxy with two open Sessions" error.

I'm guessing this has to do with Hibernate trying to use the same session to delete the Employee and Person entries in the database. Am I right? How do I solve this?