Concurrency violation

[Vik]

I create a dataadapter in code using an SQLCommand Builder and
TableMapping, and fill a dataset. After I add the rows to the datatable
(through a datagrid) and try to update/delete them, I get a Concurrency
violation error. If I close a form and open it again, everything works fine.
If I create the dataadapter in design mode, everything also works fine.
What may be wrong here?

Thanks.