.m4a issues

For me the player is not working with m4a files, which is rather crap, cause i have over 100 m4a files to use and i really don’t want to convert them into mp3 files, so can you help solving the issue.

Here is my test page
http://www.winterstormbelgium.be/Fanclub/what-lies-beneath/

first file mp3, works perfect, 2nd one is m4a just, player looks fine, but just keeps on buffering, as files to test i used these
http://en.support.wordpress.com/audio/

but, didn’t work with any other m4a file either. Please help, I really wanne have this working asap

http://ww.wp.xz.cn/plugins/zbplayer/