asterisk users - Aug 2012 - Background, Playback wave files in Asterisk 1.8.11-cert1

Hello;

What is the difference between using the Background & Playback in Asterisk
1.8 without cert and Asterisk 1.8 cert?

I surprised that in cert version, I do not hear the sound ! And it is not
working properly, but in the normal version, it is working.

So what is the new?
Is it the version? Or there are some variables or settings need to be done in
asterisk 1.8 cert that was not require in the normal version (not cert)?

Regards
Bilal