Site Problem: Can't play music from user's profile page

Site Problem: Can't play music from user's profile page

This is on my mac.

Using Chrome or Safari, I can not play music from a user's profile page. 

Ex. I can not play any of the clips from http://opengameart.org/users/bart

I can only play clips while browsing or by directly going into the clip's specific page. http://opengameart.org/content/toccata-and-fugue-in-d-minor

 

Using Firefox, I can play the clips from the user's profile page, but the 'play arrow' of the clip never changes to a 'stop square'