I had the same problem till today. I've tried everything that I found on Graphene discussions but nothing works. But today I've tried something new, pure chance. Once I've chosed the custome ringtone, mp3 or anyother, I try and still not working, like always, but then I've select the option on the top on Ringtones, NO SOUND, and the I tried to call me and SURPRISE, IT WORKS the personal ringtone. I thing its a kind of bug. I hope this works for everyone.