I got the same errors; and after much searching found this:

http://thorstenl.blogspot.com/2009/02/rpmlivnaorg-is-not-dead.html

The problem seems to be a temporary DNS fault, but the work-around in this blog page seems to have worked for me.

By the way, the line that seems to truncate according to however wide your screen is, should read:

su -c "sed -i 's|http://rpm.livna.org/mirrorlist|http://ftp-stud.fht-esslingen.de/pub/Mirrors/rpm.livna.org/mirrorlist|' /etc/yum.repos.d/livna.repo"

 Thanks to Thorsten Leemhuis for pointing me in the right direction.