Opps, sorry.When asking for help with software, you should give the name of the software and its source. In the case of your problematic font, what is its name and where did you get it?
I can find no reference in Google to a font named Gradin Symbols. I can, however, find references to Grading Symbols, which are completely different animals. The symbols used for grading papers are not to be confused with phonetic and linguistic characters.Opps, sorry.
It is called 'Gradin Symbols' and is used in linguistics and phonology. I received it from a training institute who shrugged their shoulders when I told them it would not work in OSX.