I have two tables A and B with a one-to-many relationship respectively.

On some pages I would like to get a list of A objects only. On other pages I would like to load A with objects in B attached.

This can be handled by setting the load options

DataLoadOptions options = new DataLoadOptions();
options.LoadWith<A>(a => a.B);
dataContext.LoadOptions = options;

The trouble occurs when I first of all view all A's with load options, then go to edit a single A (do not use load options), and after edit return to the previous page.

I understand why the error is occurring but not sure how to best get round this problem. I would like the DataContext to be loaded up per request.

I thought I was achieving this by using StructureMap to load up my DataContext on a per request basis. This is all part of an n-tier application where my Controllers call Services which in turn call Repositories.

ForRequestedType<MyDataContext>()
    .CacheBy(InstanceScope.PerRequest)
    .TheDefault.Is.Object(new MyDataContext());

ForRequestedType<IAService>()
    .TheDefault.Is.OfConcreteType<AService>();

ForRequestedType<IARepository>()
    .TheDefault.Is.OfConcreteType<ARepository>();

Here is a brief outline of my Repository

public class ARepository : IARepository
{
    private MyDataContext db;

    public ARepository(MyDataContext context)
    {
        db = context;
    }

    public void SetLoadOptions(DataLoadOptions options)
    {
         db.LoadOptions = options;
    }

    public IQueryable<A> Get()
    {
        return from a in db.A
               select a;
    }

So my ServiceLayer, on View All, sets the load options and then gets all A's. On editing A my ServiceLayer should spin up a new DataContext and just fetch a list of A's.

When sql profiling, I can see that when I go to the Edit page it is requesting A with B objects.