Dear Mladen,
Thank you very much for the report and I am very sorry about the issue!
We tested with importing the PDF file into Illustrator, via Save as and Publishing to PDF options, and it works fine for us. We think that it can be an illustrator problem? In Illustrator, there is an option to not have rounded ends for lines but straight cuts. Maybe it's a setting on your side? Also, it is worth checking on other things (import options/template settings in illustrator).
Please let me know if it helps!
Best regards,
Minh
Minh Nguyen
Technical Support Engineer
GRAPHISOFT