Actually it works for Ubuntu 6.10 too. Thanks to this guy who offers the solution.

sudo apt-get install gstreamer0.10-*
sudo apt-get install libxine-extracodecs mjpegtools
ffmpeg lame faad sox mplayer libxine-main1 totem-xine
wget -c http://www.debian-multimedia.org/pool/main/w/w32codecs/w32codecs_20060611-0.0_i386.deb
sudo dpkg -i w32codecs_20060611-0.0_i386.deb

Play RM under Ubuntu 7.04