in reply to
older modules Vs. Latest perl 5.12
I already posted this here 442242 answering a similar question
The CPAN autobundle can be used to ease perl upgrades, by creating a special bundle containing all the installed modules of the current version of perl. This bundle can then be installed once the new version of perl is installed.
Wrote bundle file -> /var/spool/cpan/Bundle/Snapshot_2010_8_01_00.pm
# upgrade perl here …
cpan> install Bundle::Snapshot_2010_8_01_00