I get the same exception on my system.
Note however that launchmany-curses still downloads after the exception.
Some info on my system:
net-p2p/bittorrent-5.0.7
# emerge --info
Portage 2.1.2.2 (default-linux/x86/2007.0/server, gcc-4.1.1, glibc-2.5-r2, 2.6.20.7 i686 ...