sa-update - Can't locate object method "finish"

[Steve [Spamassassin]]

Can anyone tell me why, when I run sa-update on Spamassassin 3.1.8 
(installed on Gentoo from portage) I get this message:

Can't locate object method "finish" via package 
"Mail::SpamAssassin::Timeout" at 
/usr/lib/perl5/vendor_perl/5.8.8/Mail/SpamAssassin/PluginHandler.pm line 
187.