>
>I guess thet the BindingSource implements all the necessary interfaces for me, or is that a bold assumption?

The basic issue is that when you change the value of an element in a datatable, in order to support rollback, the change is not "accepted" till you fire either of the acceptchanges or endedit methods. When you fire either method, other controls will see the changes.

When confronted by this issue I usually fire the acceptchanges method when the value of the element in question changes.

Viv pointed you to a way of doing basically the same thing via the bindingsouce, which is an intermediary between the data table and bound control. Viv's way seems more elegant but mine works, so I'll stay with it.