listen to stream with xmms or mplayer

[littleguru]

Hello

this is a month I want to listen to following site , but I can't :
http://salsastream.com/
the stream is pls type and mozila try to open audio/x-scpls helper and 
it can't.
I followed the following links instructions , but no works .
http://www.dagwoodradio.com/linuxfaq.html
http://www.yolinux.com/TUTORIALS/LinuxTutorialMozillaConfiguration.html#PLUGINS
any thing I missed , I have xmms and mplayer and both working fine .
please help ,
thanks