Hello,
Thank you Boston-Kiwi. It works! I tested printing to PDF (3D) also with ProjectWise Navigator V8i (08.11.07.171) and new 3D PDFs can be opened in Adobe Reader 9.3. correctly with all 3D features and model tree navigation.
Unfortunatley the old files still can't be reviwed in the new Reader, but now it is minor issue.
Regards
Megakalmar