Comment 8 for bug 1069019

Ok, I have tried it and as a workaround you can delete that conflictin characters from sources manually.
How to:
1º Open terminal.
2º cd /etc/apt/sources.list.d
3º Open each .list file that can't be changed as root (sudo nano irie-blender-precise.list, for example).
4º Remove (or change) any character that isn't ascii.
5º Save the file and repeat the process as needed.