si infatti ..
For k = TblRigheDocumentoDataGridView.Rows.Count - 1 To 0 Step -1
TblRigheDocumentoBindingSource.RemoveCurrent()
'TblRigheDocumentoDataGridView.Rows.RemoveAt(k)
Next
Me.Validate()
TblTestateDocumentiBindingSource.EndEdit()
Me.TblRigheDocumentoTableAdapter.Update(Me.DuilioDataSet)
ho risolto cosi..
grazie ancora..