The Medibuntu repository has been unmaintained for several months, and has become more and more useless over the years. The project is now considered abandoned, and we recommend to disable the repository if you are using it.
The project is not really needed nowadays, except for one package: libdvdcss. This package is now maintained by Jonathan Riddell at Blue Systems. It is available in a repository hosted by VideoLAN.
To disable the Medibuntu repository and enable the libdvdcss one, use these commands:
sudo rm /etc/apt/sources.list.d/medibuntu.list
curl ftp://ftp.videolan.org/pub/debian/videolan-apt.asc | sudo apt-key add --
echo "deb ftp://ftp.videolan.org/pub/debian/stable ./" | sudo tee /etc/apt/sources.list.d/libdvdcss.list
sudo apt-get update
If you are using Ubuntu saucy, you can also install libdvdcss using an alternative method (make sure to install/upgrade the libdvdread4 package first).