Castle ActiveRecord JoinedKey is not set

Question

I am using "Class Table Inheritance - Using joined subclasses" as described here: http://www.castleproject.org/activerecord/documentation/trunk/usersguide/typehierarchy.html

The following code is partly copied from there.

[ActiveRecord("entity"), JoinedBase]
public class Entity : ActiveRecordBase
{
    ...
    private int id;

    [PrimaryKey]
    private int Id
    {
        get { return id; }
        set { id = value; }
    }
}

[ActiveRecord("entitycompany")]
public class CompanyEntity : Entity
{
    private int comp_id;

    [JoinedKey("comp_id")]
    public int CompId
    {
        get { return comp_id; }
        set { comp_id = value; }
    }
    ....
}

Now when I have a CompanyEntity loaded and access the ComId property it is always 0, but the inherited Id Property contains the correct value.

Edit:

I Probably should add that our Entities are automatically generate and I do not want to touch the generator.

Edit2:

Ok, I realize that I have to touch the generator in order to make it work. But still why isn't Active Record setting the Comp_id?

Question:

How can I tell ActiveRecord to also set the value of the JoinedKey in the child class so that CompId == Id?