SDL mixer demo problem

Hey All, SDL newbie here. I’m on Ubuntu Hardy.

http://jcatki.no-ip.org:8080/SDL_mixer/

The demo code on the site above compiles with 'make"
as advised but the .mp3 I give as
command line argument does not play. I do get the following
message:

fadereu at fadeurium:~/Desktop/X/demos$ ./sdlwav song.mp3
Opened audio at 44100 Hz 16 bit stereo, 512 bytes audio buffer
fps=nan
fadereu at fadeurium:~/Desktop/X/demos$

Can anybody tell me what I need to do to make the code work?
I will be very grateful…

cheers,
------- -.-
1/f ))) --.
------- …
http://www.algomantra.com