Audio Player Plugin "File Not Found"

I’m trying to use Audio Player (v. 2.0.4.1) on a password-protected directory and keep getting nothing but “File Not Found” errors. Help!

-No other plugins are installed, so no interference there

-I have tried relative URLs to the default audio location, absolute URLs to audio posted within the password-protected directory, AND absolute URLS to audio posted to several places outside it (my site root, other people’s sites). Same difference.

-All absolute URLs that I have used have been checked and and play fine in a browser