Thanks -- progress, but one more step remains. Here's the contents of Net::POP3::SSL -- as syphilis also found out, this no longer exists in CPAN, and so I copied it form my 32 bit machine to "<perl64>/site/lib/Net/POP3/SSL.pm":

package Net::POP3::SSL;
# SSL.pm, v 1.0 2007/09/06 
use strict;

use vars qw[$VERSION @ISA];
$VERSION = sprintf "%d.%02d", split m/\./, (qw$Revision: 1.0 $)[1];

use IO::Socket::SSL; # qw( debug4 ); 
use Net::POP3;

@ISA = ( 'IO::Socket::SSL',
         grep { $_ ne 'IO::Socket::INET' } @Net::POP3::ISA );

no strict 'refs';
foreach ( keys %Net::POP3:: ) {
    next unless defined *{$Net::POP3::{$_}}{CODE};
    *{$_} = \&{"Net::POP3::$_"};
}
1;

__END__

=head1 NAME

Net::POP3::SSL - SSL support for Net::POP3

=head1 SYNOPSIS

  use Net::POP3::SSL;
  
  my $pops = Net::POP3::SSL->new("example.com", Port => 995);

=head1 DESCRIPTION

Implements the same API as L<Net::POP3|Net::POP3>, but uses
L<IO::Socket::SSL|IO::Socket::SSL> for its network operations. Due to
the nature of C<Net::POP3>'s C<new> method, it is not overridden to ma
+ke
use of a default port for the POP3S service. Perhaps future versions
will be smart like that. Port C<995> is usually what you want, and it'
+s
not a pain to specify that.

For interface documentation, please see L<Net::POP3|Net::POP3>.

=head1 SEE ALSO

L<Net::POP3>,
L<IO::Socket::SSL>,
L<perl>.

=head1 AUTHOR

Casey West, <F<casey@geeknest.com>>.

=head1 COPYRIGHT

  Copyright (c) 2004 Casey West.  All rights reserved.
  This module is free software; you can redistribute it and/or modify 
+it
  under the same terms as Perl itself.

=cut
[download]

While I get no complaints from 32 bit perl 5.8, the 64 bit perl 5.12 complains:

Not a GLOB reference at C:/opt/perl64/site/lib/Net/POP3/SSL.pm line 16
+.
[download]

So why the complaint from the newer, 64 bit perl?