if (!testDataSet.HasChanges())
  return;

BindingContext[testDataSet,  "Debug" ].EndCurrentEdit();

DataTable tblChanges = tblDebug.GetChanges(DataRowState.Added | DataRowState.Modified);
DataTable tblDeleted = tblDebug.GetChanges(DataRowState.Deleted);

if (tblDeleted != null)
  daDebug.Update(tblDeleted);

if (tblChanges != null)
{
  daDebug.Update(tblChanges);
  tblDebug.BeginLoadData();
  try
  {
    int i =  0 ;

    while (i < tblDebug.Rows.Count)
    {
      if ((tblDebug.Rows[i].RowState == DataRowState.Added) | (tblDebug.Rows[i].RowState == DataRowState.Modified))
        tblDebug.Rows[i].Delete();
      else
        i ++;
    }

    testDataSet.Merge(tblChanges);
  }
  finally
  {
    tblDebug.EndLoadData();
  }
  tblDebug.AcceptChanges();
}