VBA Function for XFDF import into Excel very slow

I found a VBA function that parses Adobe PDF Form XML data (.xfdf) into an Excel worksheet. When this code is used in a separate Workbook without anything else it works fast (<1 sec). However when I use it in the large workbook that I use to generate individual PDF reports it's extremely slow (~5 minutes!!)

I've tried adding Application.ScreenUpdating = False, Application.EnableEvents = False, Application.Calculation = xlCalculationManual and Application.Volatile (False), but it didn't help.

Any ideas are very welcome. (I'm a VBA beginner, able to copy and adapt scripts I find for my purposes...)

This is the code used:

Formula:

Sub ReadXML()



    Call fnReadXMLByTags



End Sub







Function fnReadXMLByTags()



    Dim mainWorkBook As Workbook



    Set mainWorkBook = ActiveWorkbook



    bestand = mainWorkBook.Sheets("Blad6").Range("G10").Value

    

    mainWorkBook.Sheets("Blad6").Range("A:B").Clear



    Set oXMLFile = CreateObject("Microsoft.XMLDOM")



    XMLFileName = bestand



    oXMLFile.Load (XMLFileName)



    Set ValueNodes = oXMLFile.SelectNodes("/xfdf/fields/field/value/text()")



    mainWorkBook.Sheets("Blad6").Range("A1,B1").Interior.ColorIndex = 40



    mainWorkBook.Sheets("Blad6").Range("A1,B1").Borders.Value = 1



    mainWorkBook.Sheets("Blad6").Range("A" & 1).Value = "Vraag"



    mainWorkBook.Sheets("Blad6").Range("B" & 1).Value = "Antwoord"





        For i = 0 To (ValueNodes.Length - 1)



            Antwoord = ValueNodes(i).NodeValue



                  

      'mainWorkBook.Sheets("Blad6").Range("B" & i + 2).Borders.Value = 1



     mainWorkBook.Sheets("Blad6").Range("B" & i + 2).Value = Antwoord

        

      mainWorkBook.Sheets("Blad6").Range("B" & i + 2).NumberFormat = "#"

        



    Next



    'Reading the Attributes



    Set Nodes_Attribute = oXMLFile.SelectNodes("/xfdf/fields/field")



    For i = 0 To (Nodes_Attribute.Length - 1)



        Vraag = Nodes_Attribute(i).getAttribute("name")



        'mainWorkBook.Sheets("Blad6").Range("A" & i + 2).Borders.Value = 1



        mainWorkBook.Sheets("Blad6").Range("A" & i + 2).Value = Vraag



    Next



End Function