I inherited a bit of VBA code that functions as expected in Word 2003. In Word 2010, it functions well in a DOCX document, but in a DOC document, the text box gets added to the primary header, not the first page header.

Any ideas why the code works differently depending on the document format?

Code:
Sub BuildDraftStampFirstPageHeader()
    Dim s As Shape
    Dim rng As Range
    With ActiveDocument.Sections(1).Headers(wdHeaderFooterFirstPage)
            .Range.Collapse Direction:=wdCollapseStart
            With .Shapes
            '   Create Draft text box
                If ActiveDocument.Sections(1).PageSetup.Orientation = wdOrientLandscape Then
                    Set s = .AddTextbox(msoTextOrientationHorizontal, _
                        InchesToPoints(0.175), InchesToPoints(0.175), _
                        InchesToPoints(1), InchesToPoints(0.35))
                Else
                    Set s = .AddTextbox(msoTextOrientationHorizontal, _
                        InchesToPoints(0.25), InchesToPoints(0.25), _
                        InchesToPoints(1), InchesToPoints(0.35))
                End If
            With s
                .Name = "DraftStampFirstPage"
                .Fill.Visible = False
                .Line.Visible = False
                With .TextFrame
                    .TextRange = "DRAFT"
                    With .TextRange
                        .Font.Name = "Arial Black"
                        .Font.Size = "18"
                    End With
                    .MarginLeft = 0
                    .MarginRight = 0
                    .MarginTop = 0
                    .MarginBottom = 0
                End With
                .LockAnchor = False
            End With
        End With
    End With
End Sub