Hibernate version:
2.1.6

Mapping documents:

<class name="Process" table="workflow_process">
<id name="id" column="id" type="java.lang.Long" unsaved-value="null">
<generator class="increment"/>
</id>
<one-to-one name="accounting" class="ProcessAccounting" cascade="save-update"/>

<joined-subclass name="Casting" table="workflow_pr_casting">
<key column="id"/>
</joined-subclass>
</class>

<class name="ProcessAccounting" table="workflow_pr_acc" >
<id name="id" column="id" type="java.lang.Long" unsaved-value="null">
<generator class="foreign">
<param name="property">process</param>
</generator>
</id>
<one-to-one name="process" class="Process" constrained="true"/>
</class>

Code between sessionFactory.openSession() and session.close():
Process pr = // get from somewhere (type Casting)
session.saveOrUpdate(pr);
logger.debug("pr id == " + pr.getId());
ProcessAccounting pa = new ProcessAccounting();
pa.setProcess(pr);
pr.setAccounting(pa);
Full stack trace of any exception that occurs:

Hibernate does not report any problems but saves both one-to-one-related entities with different IDs (both are incremented independently).
Does joined-subclass have anything to do with this?

Name and version of the database you are using:

MySQL 4.1

Error in Subject: Hibernate Does not throw an exception but saves a wrong ID