Serial Coroutines and ManagedThreadId

   I've run into problems when using Serial Coroutines with respect to the ManagedThreadId property on the EntityManager.  The exception specifically says that I should "Consider calling the EntityManager’s asynchronous methods; they work safely on background threads managed by DevForce. "  I thought I was using the asynchronous methods so I was expecting it to work.  An example of the code is as follows:

        public void TestCoroutine(AsyncEventCompletedCallback<GenericAsyncEventArgs<int>> callback)        {
            //Get the entity manager from somewhere
            var myEntityManager = Uow.EntityManager;

            Coroutine.Start(
                () => BuildBasicCoroutine(myEntityManager),
                op =>
                    {
                        //Always fails
                    });
        }

        private static IEnumerable<INotifyCompleted> BuildBasicCoroutine(DataModelEntityManager em)
        {
            yield return em.Users.ExecuteAsync();
            yield return em.Contracts.ExecuteAsync();
        }

If I switch it to use Coroutine.StartParallel it will succeed just fine but in many cases I actually need serial behavior becaues one query depends on a previous query.  

It seems like this should be possible and maybe I'm just doing something basic wrong.  Any help would be appreciated.