And thus, all the more reason to use a separate copy of perl that is under your control, not your distro's control. This also means things like saving off a copy of the modules you need. Stability, predictability, and control. You're no longer at the mercy of a distro that ships modules that have bugs in them (you can apply bugfixes to your private perl), nor in a distro that upgrades a module to be incompatible with you (you simply don't upgrade that module until you can fix your code to match). And you no longer care about which distro is being used - whether it's CentOS, Gentoo, SLES, Debian, Ubuntu, or whatever, you just work. Makes upgrading the distro safer, too, since you won't rely on the system perl, and you know that your stuff will keep working because its perl version is frozen to whatever you've tested.
But maybe that's just me.