Best I can tell, there is no Modern::Perl version 2011. I think you've confused the date (or, rather ,part of the date) in the title you cite with a version number.
Both CPAN and ppm list Modern::Perl-1.20121103 (for perl 5.016); a naming convention which may clarify the problem.
Comment on Re: Modern::Perl version 2011 required--this is only version 1.03 at my-perl-script.cgi