I agree that the version of Perl is likely not the problem. Among the more likely causes is a configuration issue or a CPAN module version.

But when someone is trying to debug an issue, they need to eliminate one factor at a time. And the experience of getting their application up and running from scratch against a new Perl may focus attention on what else can be broken.

Besides, perl 5.8.7 was the request, so that is what I tried to help them get.