First - note that row creation occurs as soon as you enter the new row
- so the other values might not be available at this point.

OK; two other things that occur:

1: since you are using a typed DataTable, override the OnTableNewRow
method?

           protected override void
OnTableNewRow(DataTableNewRowEventArgs e)
           {
               // use base creation logic
               base.OnTableNewRow(e);
               DataRow row = e.Row;
               // TODO: do something with row
           }

2: Listen to the ListChanged event on the binding-source; in
particular for ItemAdded:

   bindingSource1.ListChanged += bindingSource1_ListChanged;
   void bindingSource1_ListChanged(object sender,
ListChangedEventArgs e)
       {
           if (e.ListChangedType == ListChangedType.ItemAdded)
           {
               object row = bindingSource1[e.NewIndex];
           }
       }

Either of those help any? You can also listen to
ListChangedType.ItemChanged if you want to get the values during
updates - but watch out for recursion - i.e. if you set a value
whenever you detect a value has changed... you can end up going in
circlues.

Marc