DataContext update and rollback

Question

I'm having a problem with my DataContext. In the following code snippet, I first delete existing objects in my datacontext, and later in same code, adding new again. The problem is, since I'm using .DeleteOnSubmit() its still containing 2 entities in my Datacontext, tho its stored correctly in my Database.

Here the code:

public void ConnectedApartment(Apartment newApartment, Apartment existing)
{
    ConApart ConApartTemp = new ConApart();
    ConApartTemp.Apartment1 = newApartment;
    ConApartTemp.Apartment = existing;
    DatabaseConnection.ConAparts.InsertOnSubmit(ConApartTemp);
}

public void opdaterConApart(ArrayList connected, Apartment Apartmenten)
{
    foreach (ConApart sam in Apartmenten.ConAparts)
    {
      DatabaseConnection.ConAparts.DeleteOnSubmit(sam);
    }
    foreach (ConApart sam2 in Apartmenten.ConAparts1)
    {
      DatabaseConnection.ConAparts.DeleteOnSubmit(sam2);
    }

    foreach (Apartment apa in connected)
    {
      ConnectedApartment(apa, Apartmenten);
    }
    DatabaseConnection.SubmitChanges();
}

If I doesn't SubmitChanges() of the delete before

    foreach (Apartment apa in connected)
    {
      ConnectedApartment(apa, Apartmenten);
    }

Then my Datacontext will contain 2 entities, and my gui will show duplicates for each time its changing.

If I use following:

public void ConnectedApartment(Apartment newApartment, Apartment existing)
{
    ConApart ConApartTemp = new ConApart();
    ConApartTemp.Apartment1 = newApartment;
    ConApartTemp.Apartment = existing;
    DatabaseConnection.ConAparts.InsertOnSubmit(ConApartTemp);
}

public void opdaterConApart(ArrayList connected, Apartment Apartmenten)
{
    foreach (ConApart sam in Apartmenten.ConAparts)
    {
      DatabaseConnection.ConAparts.DeleteOnSubmit(sam);
    }
    foreach (ConApart sam2 in Apartmenten.ConAparts1)
    {
      DatabaseConnection.ConAparts.DeleteOnSubmit(sam2);
    }

    DatabaseConnection.SubmitChanges();

    foreach (Apartment apa in connected)
    {
      ConnectedApartment(apa, Apartmenten);
    }
    DatabaseConnection.SubmitChanges();
}

then it works, but that solution is weak for Rollback function, since it going to: 1. Delete existing objects 2. submitChanges 3. Add new objects 4. submitChanges

But if something fails between point 2 and 3, the objects that are deleted is lost. Any suggestions? How can I maintain my context, so it doesn't hang with double entities, and still handle Rollback functionality if something goes wrong???