I am trying to get m4a files to play in ubuntu 6.10

I understand that the codec to decode m4a is not installed by default.
I have done "apt-get install faac" and "apt-get install faad" which
have completed successfully.
I have also installed the GSTreamer extra plugins, Xine extra plugins
and GStreamer ffmpeg video plugin

Rhythmbox still won't play the files citing that "The GStreamer
plugins to decode MPEG-4 Audio Files cannot be found" and Totem Movie
Player returns the error "You do not have a decoder installed to
handle this file".

What am I missing to enable m4a playback?
The files are not encrypted - they are just simple CD rips through
iTunes in windows!