This is how to setup kubuntu to be able to play .rmvb file:
- Download and install SMPlayer software at http://smplayer.berlios.de/
- Or if you want to use Synaptic Software Manager, add this line to /etc/apt/sources.list:
deb http://ppa.launchpad.net/rvm/ppa/ubuntu intrepid main
alternatively, you can add medibuntu repository and install Realplayer package.
http://medibuntu.org