The licensing for MP3 patents has completely changed. Thomson Multimedia, owner of certain patents has ceased providing free access to their technology for Mp3 decoders.
Here is the pricing schedule
If any of you are operating streaming audio or encoding anything into MP3 format, please note that this format has officially shot itself in the foot. All "free" mp3 decoders (Winamp, realaudio, etc,) will now be subject to a per user licensing fee.
An alternative, for anyone interested in streaming audio is
OGG VORBIS