Go to try to make an elixer, then hit the button (checkbox?) to show the ones that you don't know. Each will list its origin - either research or a book. It is possible that all of the level 9 and lower that are available by research are known already, so until you hit 10 further research will be unsuccesful. If you still have researchable ones to learn at your current skill, then you may be a victim of some sort of bug.