I'm not sure I understand the question completely, so I apologize in advance if this is unhelpful.

Different versions of Perl, by default, do not share installed modules. This is for two very good reasons. First, the internals of Perl can change between releases. Any compiled module, such as DBI, may or may not work without being recompiled for the other version. If modules were shared, you'd get hard-to-debug missing symbol errors. Second, core modules are allowed to depend on new features introduced in that version of Perl. Several core modules in 5.8 use the our keyword introduced in 5.6.0. Using those modules on an earlier version would cause syntax errors.

In this case, a lot of the work done to File::Spec and friends improved portability on platforms like VMS (and Mac OS 9, I believe). If version 1.1 works fine for you, I'd suggest sticking with it.