Iterations of WritePlacedElement are loosing original placement

I have two processes, ran in sequence, which use a similar technique to take PDF pages from input file(s) and append them to an output file. My append-page routine accepts a pdftron.PDF.Page and optional horizontal and vertical offset to shift the page in the output stream. I am only shifting the first page of each 19 page merged-in docoument. Basically...

Public Sub AppendPDFPage(ByVal pg As Object, Optional ByVal horizOffset As Single = 0, Optional ByVal vertOffset As Single = 0)
    Dim elm As Element
    elm = pdfout.mEB.CreateForm(pg, pdfout.mDoc)

    Dim Gstate As PDF.GState

    Gstate = elm.GetGState
    Gstate.SetFillColor(New ColorPt(Color.R / 255.0, Color.G / 255.0, Color.B / 255.0))

    If (horizOffset = 0) And (vertOffset = 0) Then
             elm.GetGState.SetTransform(1, 0, 0, 1, -horizOffset * 72.0, vertOffset * 72.0)
        Dim logoRect As New Rect
        elm.GetGState.SetTransform(1, 0, 0, 1, CDbl(Me.HItoPt(horizOffset, 2)), CDbl(Me.VItoPt(vertOffset, 2)) - logoRect.Height)
    End If

End Sub

Works wonderfully on the first iteration... The 2nd generation PDF has that first page shifted exactly as expected (my params are in inches from top left corner).

Second process runs, requesting NO shift, and I loose the shift made by the first process in the 3rd generation.

I do not suspect any pdftron problem, but rather I suspect I need to be looking at something on the input page so that my default page shift is not necessarily zero, or at least is calculated additively.

Could you please provide a full code sample (e.g. a drop-in replacement for ElementEdit sample) so that we can take a look at it. Thx!

I have built a simplified VB project demonstrating the issue. I have a sample input PDF file. I have isolated the issue to a routine NOT shown below which attempts to clear any text items intersecting with a rectangle that is a portion of the page. I can ZIP it all up and send to you. Can you please give me an e-mail address to use that will not publish the ZIP to public forums (because of sample input PDF)?

Thanks so much for your help.

Best regards- Lee