I noticed a few problems in your script. You're doing way too much. I cleaned it up and fixed the problems.

#!/usr/bin/perl

use strict;
use warnings;
use LWP::UserAgent;
use HTTP::Request::Common;

my $proxy = 'http://72.43.50.184:80/';
my $contentget = 'http://search.cpan.org/~gaas/libwww-perl-5.837/lib/L
+WP/UserAgent.pm'; 

my $ua = LWP::UserAgent->new;
$ua->timeout(30); 
$ua->proxy(['http'], $proxy);

my $res = $ua->get($contentget);
if ($res->is_success) {
    print $res->decoded_content;
} 
else {
    die $res->status_line; 
}
[download]