You could basically find out if the webserver or anything in that environment is causing the problem.
php.exe -f path/to/file.phphttp://www.php.net/manual/en/features.commandline.php
php.exe -f path/to/file.php
<?php 
php
function get_lfsw_data($query_str) {
    sleep(5);
    if ($gzstr = file_get_contents('http://lfsworld.net/pubstat/get_stat2.php?version=1.3&c=2'.$query_str)) { 
        if ($str = @gzuncompress($gzstr)) 
            return $str;
        else
            die($gzstr);
    } else {
        return -1;
    }
}
echo get_lfsw_data('&action=wr&idk=".$this->id_key);
?>

<?php 
    function get_lfsw_data($query_str) {
        sleep(6);
        $query = "http://lfsworld.net/pubstat/get_stat2.php?version=1.3".$query_str."&c=2&idk=".$this->id_key;
        if ($gzstr = file_get_contents($query)) {
            if ($str = @gzuncompress($gzstr)){
                return $str;
            }else{
                die($gzstr);
            }
        } else {
            return "";
        }
    }
?>

 
)
<?php 
$teams = $LFSWorld->get_teams();
echo "<p>Starting teams list</p>\n";
foreach ($teams as $this_team) {
    echo "-----------------------------------------\n";
    echo "Team: {$this_team['team']} ({$this_team['tag']}) \n\n";
    echo "Members: {$this_team['nr_members']} \n";
    echo "Website: {$this_team['url']} \n\n";
}
echo "<p>Finished teams list</p>\n";
?>
include 'lfsworldsdk.php';
class MyLFSWorld extends LFSWorldSDK {
	function teams_test() {
		$teams = [B]$this[/B]->get_teams();
		echo "<p>Starting teams list</p>\n";
		foreach ($teams as $this_team) {
			echo "-----------------------------------------\n";
			echo "Team: {$this_team['team']} ({$this_team['tag']}) \n\n";
			echo "Members: {$this_team['nr_members']} \n";
			echo "Website: {$this_team['url']} \n\n";
		}
		echo "<p>Finished teams list</p>\n";
	}
}
<?php 
//$LFSWorld = new LFSWorldSDK();
$LFSWorld = new MyLFSWorld();
$LFSWorld->teams_test();
?>
<?php 
return gzinflate(substr($str, 10));
?>



<?php 
php
class MyLFSWorld
{
    var $LFSWorld = null;
    function MyLFSWorld($idk)
    {
        $this->LFSWorld =& new LFSWorldSDK($idk);
    }
}
?>

)
 So please do not take it as a serious approach for anything useful - i really just played with your SDK methods (and PHP in general). 
)
<?php 
global $LFSWorld;
?>
<?php 
global &$LFSWorld;
?>
<?php 
function get_lfsw_teams(&$LFSWorld) {
  // ...
}
$LFSWorld = new LFSWorldSDK($idk);
get_lfsw_teams(&$LFSWorld);
?>
 
preg_match_all('/(.+)\s(.+)\s(.+)\s(.+)/U', $data, $fragment);