When emerging gentoo-stats, the program would not start, complaining that it can't find UserAgent.pm. What fixed this problem for me is emerging libwww-perl and libnet. I looked at the .ebuild of gentoo-stats, and it seems to only list perl as a dependency.
Hmm, in my gentoo-stats-1.0.ebuild, it says. I've never committed another version of this ebuild, it's the very first one. RDEPEND=">=sys-devel/perl-5.6.1 dev-perl/libwww-perl" DEPEND=""