Audio Player

I have 2 Problems with the plugin:

1) I don’t know what settings I have changed, but the player on my site used to work. Now it’ll take me to a 404. If I copy the link, and insert it into a browser, I can see that the link is correct (save as dialog opens). Also the download link doesn’t work anymore, same problem.

2) after pressing play in a new window, the new window opens and plays the file, but the initial page is changing to the 404 page.

any ideas?

http://www.zweibuenzlis.ch/die-praktikantin-s01e04/

http://wordpress.org/plugins/powerpress/