Why is my tab directory hidden in a PDF

I have created a FM-book (V12) consisting of a number of files. One of these is a Tab directory for the binder the documents shall be placed in. The tabs are created in a table in the tab directory file. I also want a PDF-solution for the documents and in this I wish the tabs i the tab-directory to be active links to the differnet documents. So I created hypertext links between the Tab-directory and the first page of each document in FrameMaker. Works beatiful.

However, when I create a PDF of the book the tabdirectory table is whitened out. The links are there and works but the tab-texts are hidden. Note that there is other text in the tab directory document that is not blanked.

Any ideas why?

I even removed the links and regernerated the PDF but the tabs remain hidden.