I recently upgraded to the lang/perl-5.14 from lang/perl-5.12.
The lang/perl-5.12 in it turn was upgraded from lang/perl-5.8.
I notice that more modules formerly installed from separate ports are included
in that port. This led me to the duplicates of the ports and I deleted them by
mean of my Inclusure utility: 
    http://gitweb.vereshagin.org/inclusure
    https://github.com/petr999/inclusure
Such a ports in question make more disk space used and may lead to the strange
things to happen on the system, at least their files may conflict in the 'man'
and 'bin' directories as shown here with 'converters/p5-JSON-PP' port.
I'm pretty sure  there should be the CONFLICTS added to teh eveery
'lang/perl5.X' port to avoid confusion.

Fix: Put CONFLICTS into the lang/perl5.14/Makefile on those packages:
    $ pkg_info -L perl-5.14.1 | perl -Mstrict -Mautodie -wE 'open my $fh, "<", "/usr/ports/INDEX-7"; my %ports; while(my $line = <$fh>) { chomp $line; $line =~ s/^([^|]+)-[\d\.,_]+\|.*$/$1/g; $ports{ $line } = 1; } close $fh; while(<>) { if( m%/usr/local/lib/perl5/5.14.1/(mach/)?(.+)\.pm$% ) { my $mod = "p5-".($2 =~ s%/%-%gr); if( defined $ports{ $mod } ) { say $mod; } } }'

Patch is supplied.

Patch attached with submission follows:
How-To-Repeat:     # portinstall lang/perl5.12 
    # portinstall converters/p5-JSON-PP
    [..]
    Installing /usr/local/man/man1/json_pp.1
    [..]
    Installing /usr/local/bin/json_pp
    # pkg_delete -fx perl-5 && cd /usr/ports/lang/perl5.14 && make install &&\
    > perl-after-upgrade -f
    # pkg_delete -x p5-JSON-PP
    pkg_delete: '/usr/local/man/man1/json_pp.1.gz' fails original MD5 checksum -
    not deleted.
    pkg_delete: '/usr/local/bin/json_pp' fails original MD5 checksum - not
    deleted.
    pkg_delete: couldn't entirely delete package (perhaps the packing list is
    incorrectly specified?)