EntitiesMock.ObjectSet.cs fails with AddObject


First I would like to say what great tool for use with the EF. However my first test fails in AddObject(T entity) when I try to add a new single entity to the Repository. I have an entity with the following fields, however the primary key is a composite key of the TAG_AGENCY_ID, and TAG_SERIAL_NUMBER. When I try to add the entity the HasIdProperty returns true and try's to autogenerate a key. However since there are 2 fields in the set that contain ID is the name it trys to auto-generate. Wouldn't it be better to assume that if the entity being passed contained all the key values that made up the composite key that it would try to auto-generate. Of course I can change the code manually but if I regenerate from entity changes I'm broken.
[System.CodeDom.Compiler.GeneratedCode("ADO.NET Unit Testable Repository Generator", "0.5")]
public partial class TRANSPONDER_STATUS
    public virtual decimal TAG_AGENCY_ID  
    public virtual decimal TAG_SERIAL_NUMBER    
    public virtual Nullable<decimal> FILE_ID    
    public virtual Nullable<decimal> TAG_VALID