What is wrong with my code?

If I just bind the GetTable dataset gives me the right data. But If I add the relation with this empty table, gives me any empty table with only one column ("Column 0"). It should display my primary table  with an option to expand (+).

            Dim ds As DataSet = GetTable()
            If ds IsNot Nothing Then
                Dim dt As New DataTable("Temp")
                dt.Columns.Add("ID")
                ds.Tables.Add(dt)
                ds.Relations.Add(ds.Tables(0).Columns(0), ds.Tables("Temp").Columns(0))
            End If

            Me.UltraGrid1.DataSource = ds