I do chages in a Dataset and the property RowState don't take the value CHANGED

Question

The fallowing code isn't doing well sqlDataAdapter.Table1[0].X = 900; sqlDataAdapter.Update(sqlDataAdapter.Table1); Because The property RowState is unchanged. The normal is that when I change the Dataset , the DataAdater do this change in the Data Base but when I change something in a Dataset andI will update that with the DataAdapter asociated. The DataAdapter verify if the dataset has some change and aply the SelectCommand, InsertCommand or DeleteCommand for update de Data Base. The problem is that when I change the DataSet the property of him is UNCHANGED when it has to be CHANGED. What happen with that property?