I had this same error message using DBI. See bug reports at http://bugs.activestate.com/ using link for "5.6 and later" and search on both 1486 and TieRegistry.pm individually to see this error message has been a long standing "feature" in TieRegistry.pm module.

Someone on the DC Perl Mongers mailing list found a reference for me (which I cannot direct you to at the moment, but will look for it) which suggested that the warnings code logic within TieRegistry.pm has a snarl and by *gasp* not using the -w during production (but using -w faithfully in development) I could suppress this *bogus I hope* error message. This informant also observed that since Perl automagically cleans up that this error, while seeming alarming, doesn't seem to effect the processing.

Since this error occurs 12 times for me when each of 12 DBI-using Perl programs I run as a batch finish execution, I have painstaking confirmed (at least to my satifaction and in my case) that I can safely ignore this error during my production runs (and safely hide it by not using -w).

Update (minutes after your update):   I see you found a solution WHILE I was writing this response. I'll make sure I'm in 5.6.1 at work as well and hope this fixes my error message in TieRegistry.pm while using DBI! Thanks!