Instead of upgrading Perl, downgrade your XML module(s). I fear someone made a big mistake allowing these modules to be upgraded on older versions of Perl without raising huge warning bells since such causes a major reduction in their functionality.

Sorry, I wish I had more details. I've seen this problem lots of times but so far I've only been on the edge watching it happen, not actually involved. I hope my posting will encourage someone with more details to respond. (: