I recorded a sound, saved it as an mp3 file and copied it to the Ringtones folder. I then went to settings, sound, phone ringtone and selected the new file. It played the sound correctly. When I receive a call it does not play, one of the totally useless Samsung tunes plays.
I then selected it as a custom sound for a particular person and it does play correctly when she calls.
Have I missed a vital step? I really do not like any of the supplied tunes.