Are you on a mac or PC? And what font management are you using? Doctor? Suitcase? Etc etc
Have you tried taking the font out of your files and re-installing it into the Suitcase or the Font folder in Windows???
Mac. I'm not using any font management.
There are a coupleof folders on my system with fonts in them its very confusing.
Hmm ok are there any other packaged files you have with that particular font in it that you could try and link from?
You sure there are no font managment applications on your system?
The other thing is try doing a search of your system to see where it is stored, and see if that comes up with anything??
You could have a corrupt system font cache. You can use Suitcase Fusion to clean your font caches, or use a product like FontNuke to do so.