gpg --keyserver subkeys.pgp.net --recv-keys 3FC8DEE9
gpg -a --export 3FC8DEE9 | sudo apt-key add -
add to /etc/apt/sources.list 
#
# ofth.de Paket
deb http://repo.ofth.de/debian lenny main contrib non-free
deb http://repo.ofth.de/debian lenny-backports main contrib non-free
aptitude update; aptitude install debian-ofth-keyring