I want make three custom ringtones, and I succeeded on one. Here's exactly what I did:
Last week, for the first contact, I transferred an MP3 file to the Downloads directory on the Thunderbolt using Windows Explorer with the phone connected to the computer with the USB cable. I went to the contact (People icon on the home screen) and selected Ringtone. The new one was in the list, I selected it, no problem.
Last night, I tried to do the same thing for the other two. I connected the phone and transferred two MP3 files to the Downloads directory (and verified they are there). I selected one of the two People and selected Ringtone; the two files were _not_ in the list of ringtones available.
How did I go wrong?