About 24 months ago I purchased a version of KavaSoft’s Translation Service application for the Mac. With the recent move from my old Powerbook to my new MacBookPro the application stopped working. Apparently the licence is tied not just to your purchase but to the computer you installed it on.
As I had used the Apple migration tool to move everything across to the new laptop, Translation Service stopped working. I dropped an email to the developer and literally got an email response 60 minutes later with an updated licence.