ok guys, found it...
The option SO_BROADCAST requests permission to send broadcast datagrams on the socket. Broadcast was a privileged operation in earlier versions of the system.
so, I rewrote my snippet:

#!/usr/bin/perl
#
use strict;
use IO::Socket;

# defaults
my $bcaddr = '192.168.254.255';
my $port = 9870;

socket(sock, PF_INET, SOCK_DGRAM, getprotobyname("udp"))
    or die "socket:$@";
setsockopt(sock, SOL_SOCKET, SO_BROADCAST, 1)
    or die "setsockopt:$@";

my $dest = sockaddr_in($port,inet_aton($bcaddr));

# 10 udp's on the wire
for (my $i=0;$i < 10;$i++) {
    my $data = 'UDP packet ' . $i;
    # send udp packet
    send(sock,$data,0,$dest) || die "send(): $!";
}
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doesn't seem to work with IO::Socket::INET->new
thanks for the tips! made me look further than Perl (C, kernel)...