i have 10.3.9 macosx with perl v5.8.1-RC3
and those modules are not in the default installiation
of perl, and while you upgraded macosx itself, you got
new version of perl, without modules you had installed
before upgrade, i usualy have the same problem after
upgrading perl on my freebsd box, i just reinstall
modules via ports or cpan shell, you should do the same.
using cpan shell, i gues is the best way for you.