What are you actually doing? You have code that needs Perl 5.8.8 and you make what pretend that you have something more modern than 5.6.1?
update: aha, reading the below reply it all becomes clearer, even to me. You HAVE both 5.6.1 and 5.8.8, but the default environment is for 5.6.1? Then Andreas advice is very good.