Convert several documents with one page into one document with 4 file per page: Some files appear in wrong order

[Johann-Tree]

I use this great tool to convert the shipping labels from DHL which I get as a private customer in A4 format, with each label as a separate file. Only half the page is needed on the parcel. The final PDF has 4 shipping labels per page.
To only have the needed half of the page from each file I use rotation and horizontal & vertical shift.

Today I discovered that

• on page 1 PDF files 3 and 4 are interchanged,
• on page 2 PDF files 6 and 7 are interchanged.
  On the third page, the files are in the correct order!

For this purpose, this bug is not a problem but it might be under other circumstances.
See here the screenshots taken of the previews:

This is the project file I used (.txt added to be able to upload here, remove to use the file):
DHL-PDF-Paketmarken_kombinieren-4_auf_A4-.ini

The input PDFs and the output PDF:
input-1.pdf
input-2.pdf
input-3.pdf
input-4.pdf
input-5.pdf
input-6.pdf
input-7.pdf
input-8.pdf
input-9.pdf
input-10.pdf
input-11.pdf
input-12.pdf
output.pdf

[Averell7]

Thanks for reporting, you are right, this is an old bug never fixed. The main problem of PdfBooklet is that unfortunately, I no longer find time to develop it. This is a pity because it could be improved. I'll see if I can fix this.