If I follow the format [audio: http://www.mysite.com/audio/filename.mp3, sometimes it will play and sometimes it gives a file not found. But if I make any update to the post (not the audio entry, but the post text), I'll get a File Not Found from then on.
I've tried uploading via the control panel, entering the URL manually, and anything else I can think of. Either something's wrong with the plugin or it doesn't like my theme (Lightword 1.5.5).
Any help is appreciated!