Did you actually added it to the plist File?
Here’s a short introduction how to do this:
http://codewithchris.com/common-mistakes-with-adding-custom-fonts-to-your-ios-app/
Greetings,
Alex
EDIT:
Actually I tried to add my own fonts to my with the interface Builder and it doesn’t work.
Seems to be a bug…
This bug only appears, when I use an attributed String