PDF/A-3a conversion with document level attachment

[David Černý]

Hello, we are evaluating PDFNet SDK, but we have following problem:
we use this code to test PDF -> PDF/A-3a conversion:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

using pdftron;
using pdftron.Common;
using pdftron.SDF;
using pdftron.PDF;
using pdftron.PDF.PDFA;

namespace _Test
{

    class Program
    {

        static void Main(string[] args)
        {
            string output_path = @"D:\!Home\TMP\";
            string input_path = @"D:\!Home\TMP\";
            string pdf_file_name = output_path + "test.pdf";
            string attachment_file_name = "sample_image.png";
            PDFNet.Initialize();
            //create PDF with attachment
            using (var doc = new PDFDoc())
            {
                doc.PagePushBack(doc.PageCreate());
                doc.AddFileAttachment(attachment_file_name, FileSpec.Create(doc.GetSDFDoc(), input_path + attachment_file_name,true));
                doc.Save(pdf_file_name,0);
            }
            //convert to PDF/A-3A
            using (PDFACompliance pdf_a = new PDFACompliance(true, pdf_file_name, null, PDFACompliance.Conformance.e_Level3A, null, 10, false))
            {
                pdf_a.SaveAs(pdf_file_name + "_PDFA-3A_ByPdfNet.pdf", true);
            }
        }


    }
}


This code finishes without any error and resulting pdf "test.pdf_PDFA-3A_ByPdfNet.pdf" is successfuly validated by Adobe Acrobat XI, but the document level attachment "sample_image.png" in "test.pdf_PDFA-3A_ByPdfNet.pdf" has unknown size and cannot be openned.
Attachment in "test.pdf" (pdf file before conversion) is ok.

Thank you for assistance.