Uploaded MP3 is returning No Content

Hi there, I'm having a problem with a client's site.

It is a mapped domain. The file has 644 permissions and is owned correctly.

When the file is accessed, it returns 204 no content. The file is being found, but it's content is being truncated by the server and I'm not sure why.

I believe this started with the 3.6 upgrade.

The server is also storing png's in the same folder and they are being served correctly. MP3's however are not.

Any ideas on how I can get this to properly work?

I also checked the MP3 file and saw that it did have content and was not null.

The file in question is available here:
http://desertsax.com/files/2012/07/I-Shot-the-Sheriff-3.mp3