Here you go. Now tested. It fetches the url every 5 seconds ad nauseum, and no leaks.

#! perl -slw
use strict;
use threads;
use threads::shared;
use Thread::Queue;
use LWP::UserAgent;

sub t {
    my $Q = shift;
    while( $Q->dequeue ) {
        my $ua = LWP::UserAgent->new;
        my $response = $ua->get(
            'http://www.mektek.net/mekmatch/listServersRss.mkz'
        );

        my $rss = $response->decoded_content
            if $response->is_success;

        print $rss if $rss;
        print "done1";
    }
}

my $Q = new Thread::Queue;
my $thread = threads->create( \&t, $Q );

require Win32::GUI;

my $mw = Win32::GUI::Window->new(
    -width => 1000, -height => 800,
    -title => "Test", -name => "Test",
    -onTimer => sub {

        $Q->enqueue( 1 );

    }
);

my $use_up_some_memory = "x" x (1024 * 1024 * 20);

$mw->AddTimer( "T1", 5000 );
$mw->Show;

Win32::GUI::Dialog();
$Q->enqueue( undef );
$thread->join;
[download]