mp3inline / play mp3 in one post

I’m trying to use the mp3inline plugin. Tried the other version, inline-mp3-player, too. I can’t get either to work. I uploaded one mp3 to my wp-content/uploads folder. The path of the uploaded mp3 now starts with ftp://. Is that correct? I paste its path into the post link field, save, preview, etc. I’ve read every thread on the plugin, and the plugin author’s site. Can’t find what’s wrong.

Here’s one thing: when clicking on the link to the mp3, the song tries to load, then asks for my website password. Perhaps I’ve uploaded it to the wrong folder?