I remember back in the olden days, a lot of modules would require perl 5.6 and cpan would keep trying to download perl-5.6.tar.gz. That was irritating on dialup.

Ah, fond memories. This was a bug in the dependency analysis of CPAN.pm itself. Andreas König fixed up CPAN.pm to avoid doing this. But you still had to upgrade your local CPAN distribution to get the fix.