PDFsharp & MigraDoc Foundation

Hello, i want insert a pdf into another pdf version 1.3; in pdf version 1.4 it's ok, but with the same program with old version not do correctly the same operation; when i open the new pdf the image not compare and iriceve a messagge "token q not recognize".

I report my code.

Thank you very much.

nome_file_tmp = val_nome_file_tmp + ".pdf";
PdfPage page = document.Pages[idx];
XGraphics gfx = XGraphics.FromPdfPage(page);
XImage image1 = XImage.FromFile(nome_file_tmp);
gfx.DrawImage(image1, 0, 0);
File.Delete(nome_file_tmp);
image1.Dispose();
gfx.Dispose();
page.Close();