Ok I solved my particular issue.  My generic repository was built up from ObjectContext instead of the context created by the entity framework designer.  As soon as I specified the exact context it all started working.  Not sure this is cool though. 

Code was:

public abstract class BaseRepository<T> : Repository<T> where T : class

    {  

    protected ObjectSet<T> _objectSet;

       protected ObjectContext _objectContext;

       public BaseRepository(String stringconn)

        {  

           this._objectContext = new ObjectContext(stringconn);  //changed here to specific context

                       _objectSet =this._objectContext.CreateObjectSet<T>();

        }