dataset. has changes problem

[AndreAraujo]

hi everyone, i have a form that is binded to 2 datatables in the same dataset.
i need to determine if tha values where changed when i move to the next record or when leave the form.
I use the DS.haschanges but i get haschanges= true when i move to the next record but the data was not changed.
and DS.haschanges= false when i change the data and press my save button.
the code in my Save button

Me.BindingContext(Ds.Tables).EndCurrentEdit()
if Ds.HasChanges Then
  If MsgBox("Save?", MsgBoxStyle.Question +                msgBoxStyle.YesNo) = MsgBoxResult.Yes Then
                update_data()' function update
  End If
End If

Any ideas.

Thanks
Andre