Audio Player only streaming part of complete File

We host a collection of downloadable sermons.

The sermon downloads without any difficulty, but the moment you attempt to listen to the sermon via the audio player, it will often (but not in every case) only stream a few minutes of the file.
http://www.hbconmain.com/sermons/?sermon_id=528

Deleting the file and re-uploading it doesn’t have any impact on the problem.

any assistance would really be appreciated.

thanks

http://wordpress.org/extend/plugins/audio-player/