clearing deleted items from a collection of child objects

I have a grid of users on a winform and call a upate form to update the users and add/remove user roles. this is all derived form the ideablade role based tutorial.

I am having a problem with refreshing a grid detail view (dev express grid) after I delete one of the child detail items (user roles)

below is my form load and load user methods

I am using a span to get the userroles. before I added the span, the grid view of the parent user table was being refresh but not the related child user roles. after the span, new roles for the user that I add do show up but roles that I remove still are in the users object(user.user_roles).

When I return from the update form, I post a event back the grid window, and from that event I call load_users.

the debugger is clearly showing that deleted objects are not being cleared from the users object, even though they have been deleted from the sql server database.

What do I need to add to clear the deleted items?

private void UserBrowse_Load(object sender, EventArgs e)

{
//mPersMgr = PersistenceManager.DefaultManager;

mPersMgr = new PersistenceManager(CommonUser.CurrentUser.PersistenceManager);

InitializeBindingNavigator();
users.ApplySort(EntityPropertyDescriptors.User.UserName, ListSortDirection.Descending, true);

usersBS.DataSource = users;
userRolesXGBM.GridView = usersXGBM.AddRelationView("My User Roles", "MyUserRoles");

gridView1.LayoutChanged();
Load_Users();
}
void Load_Users()

{
mPersMgr.DefaultQueryStrategy = QueryStrategy.DataSourceOnly;

mLastQueryTs = DateTime.Now.AddMilliseconds(-mAsyncPeriod);

EntityQuery e = new EntityQuery(typeof(User));

e.AddSpan(EntityRelations.User_UserRole);

users.ReplaceRange(mPersMgr.GetEntities<User>(QueryStrategy.DataSourceOnly));

}