The problem is not with the PDF files. If these work fine in Adobe Reader then it's the application that doesn't handle the file properly. The problem is encountered when the PDF file was created with a modern version of Acrobat or with any other PDF creation software. Also, Livelink could have trouble displaying certain elements from the PDF file. This does not usually happen, but in some cases this might be the error. I advise you to switch to Adobe Reader if the Livelink offers the same features related to PDF viewing.
Since you depend on Livelink, I recommend getting the PDF documents with the software in question and use Acrobat as viewing where is the case. It involves the use of two applications but it works.