CMdaAudioPlayerUtility problem...

Hi people.

I have a big problem. I make a small program that play a song in midi format. It is based in:
http://www.newlc.com/article.php3?id_article=38

But the problem is:
It works perfect in 7650 and 3650...
It fails in 6600 (without error, simply mute).

What is the problem?

Thanks