I usually store all my music, documents, and other personal files in the external sd card. So I have my ringtone to be used from my external_sd. I've seen that if the external sd card is being in use ...
I've assigned a default ringtone and one other ringtone to my wife. She called me two days ago and the phone played the Galaxy SII ringtone. Next day, somebody else called me, and the same happened. ...