I've got a number of MP3 ringtones saved in the media/ringtone folder on my SD card. Once upon a time, I could assign one of these as a primary ringtone and that's what I'd get when someone called. For the past few months, however when I assign an MP3 in Settings/Sounds/Phone Ringtone it reverts to a stock ringtone--''Windchime" I think it's called. Not unpleasant, but not what I want to hear. I don't have the same problem with notifications or alarms, although I use the same MP3 files for those--can anyone help me sort it?