Index not working in PDF

Hello all,

I have not used PDF in a very long time, as all of my work is online. But now a client asked me to solve a couple of problems with their structured FM setup and one of them is making the links in the index work in PDF. Generating the PDF with the usual job options makes the hand appear over the page numbers, but the click does not lead anywhere (not even a non-existing target). I have tried switched on named destinations in the PDF settings but no difference.

Can anyone tell me how the PDF generation is supposed to pick up the index markers ?

Thanks

4everJang