Hello Paul and Chris,
I have some machines (RH73 and Fedora) where iftop (both 0.15 and 0.16) segfaults. Ik know there were problems with RH72 and ncurses, but this is ncurses-5.2-12 on RH73 and higher.
# rpm -qa | grep ncurses ncurses-5.2-12 ncurses-devel-5.2-12
I'm not a programmer, but I gdb'd the core. It's here:
http://www.lucassen.org/divers/iftop.gdb.gz
HTH,
Richard.