I wonder whether there has been a change in the standard Perl license recently. I just stumbled about this:
This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.8.2 or, at your option, any later version of Perl 5 you may have available.
as created by 5.8.2's h2xs as the "COPYRIGHT AND LICENSE" disclaimer. Have to investigate.