What surprise me is that people still trying to advice to "upgrade perl" again and again. Why??
Because it's not worth my volunteered time to remember all of the bugs fixed in the 17 versions of Perl released since Perl 5.8.8, seven and a half years ago, just as it's not worth p5p's volunteered time to support the 17 versions of Perl released since then. I'll give you my best advice, filtered by all of my experience, but if I've run into problems in previous versions of Perl that I think you're likely to run into, and if they've been solved by subsequent releases, that's actionable information you really ought to know. Ignore it if you like.