Hello,
First of all, thanks for this truly impressive product! 
Now, over to a problem which I tried to overcome most of yesterday.. 
I have a table-per-class hierarchy mapping with a superclass and a subclass. 
In addition I have a third table/class which I want to associate to the subclass. It looks like this:
Code:
TABLE1 --+--> SuperClass (has property "assocKey")
         |
         +--> SubClass
TABLE2 -----> OtherClass
               <many-to-one>
                   class="SubClass"
                   property-ref="assocKey"
The reason I'm using property-ref is that assocKey is not the
primary key of SuperClass.
When loading the mapping into Hibern8 IDE I get the following
errormessage:
net.sf.hibernate.MappingException: property-ref not found: assocKey in class: SubClass
So, it almost looks like SubClass doesn't inherit the property assocKey
from SuperClass. I have also tried to add assocKey to SubClass (which doesn't make sense, and instead I got another errormessage).
The generated SubClass (from the hbm.xml file) do extend 
SuperClass
More detailed mapping follows:
SuperClass and SubClass mapping:
Code:
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
    "-//Hibernate/Hibernate Mapping DTD 2.0//EN"
    "http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd" >
    
<hibernate-mapping>
<class name="SuperClass"
    table="TABLE1"
>
    <id
        name="id" 
    </id>
    
    <discriminator column="DISCR_COL" type="java.lang.String"/>
       
    <property
        name="assocKey"
        column="ASSOCKEY"
        type="java.lang.String"
        length="19"
    />
    <!-- subclasses -->
    
    <subclass name="SubClass"
        discriminator-value="contractor">                  
    </subclass>
                    
</class>
</hibernate-mapping>
OTHERCLASS mapping:
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
    "-//Hibernate/Hibernate Mapping DTD 2.0//EN"
    "http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd" >
    
<hibernate-mapping>
<class  name="OtherClass"
    table="OTHERTABLE"
>
    <id (...)
     </id>
        
    <!-- associations -->
    
    <many-to-one
        name="subClass"
        class="SubClass"        
        property-ref="assocKey"
        unique="true"/>
</class>
Stack trace when loading the mapping:
 [java] net.sf.hibernate.MappingException: property-ref not found: assocKey in class: SubClass     [java]     at net.sf.hibernate.cfg.Configuration.secondPassCompile(Configuration.java:610)
     [java]     at net.sf.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:732)
     [java]     at net.sf.hibern8ide.Hibern8IDE.initialize(Hibern8IDE.java:171)
     [java]     at net.sf.hibern8ide.Hibern8IDE.reconfig(Hibern8IDE.java:160)
     [java]     at net.sf.hibern8ide.Hibern8IDE$6.configurationChanged(Hibern8IDE.java:586)
     [java]     at net.sf.hibern8ide.ConfigurationUI$ApplyConfig.actionPerformed(ConfigurationUI.java:245)
     [java]     at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1786)
     [java]     at javax.swing.AbstractButton$ForwardActionEvents.actionPerformed(AbstractButton.java:1839)
     [java]     at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:420)
     [java]     at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:258)
     [java]     at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:245)
     [java]     at java.awt.Component.processMouseEvent(Component.java:5100)
     [java]     at java.awt.Component.processEvent(Component.java:4897)
     [java]     at java.awt.Container.processEvent(Container.java:1569)
     [java]     at java.awt.Component.dispatchEventImpl(Component.java:3615)
     [java]     at java.awt.Container.dispatchEventImpl(Container.java:1627)
     [java]     at java.awt.Component.dispatchEvent(Component.java:3477)
     [java]     at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:3483)
     [java]     at java.awt.LightweightDispatcher.processMouseEvent(Container.java:3198)
     [java]     at java.awt.LightweightDispatcher.dispatchEvent(Container.java:3128)
     [java]     at java.awt.Container.dispatchEventImpl(Container.java:1613)
     [java]     at java.awt.Window.dispatchEventImpl(Window.java:1606)
     [java]     at java.awt.Component.dispatchEvent(Component.java:3477)
     [java]     at java.awt.EventQueue.dispatchEvent(EventQueue.java:456)
     [java]     at java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java:201)
     [java]     at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:151)
     [java]     at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:145)
     [java]     at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:137)
     [java]     at java.awt.EventDispatchThread.run(EventDispatchThread.java:100)