install rtorrent
apt-get update
apt-get upgrade
apt-get install rtorrent
remove rtorrent and libtorrent, leaving dependencies installed
apt-get remove rtorrent libtorrent10
download latest versions from
http://ftp.uk.debian.org/debian/pool/main/r/rtorrent
http://ftp.uk.debian.org/debian/pool/main/libt/libtorrent
install, force if necessary
dpkg -i libtorrent*
dpkg -i [--force-all] rtorrent*