problem with cookies

[ultimate-fun]

when i run my website through .co.nr the log in system dosnt work right. they say in there forums that it is the problem but its because the cookies arnt set up right.

here is exec.php

<?php

$ip = mysql_escape_string($_SERVER['REMOTE_ADDR']);
$time = time();
$time2 = $time - get_user_config("name=onlinetime");

$user = get_logged_in_user();
if ($user==false) {
$user['id'];
}

// Clear out this user's sessions, as well as any other sessions that are older than $time2.
$qadd = '';
if ($user['id']!=0) $qadd="OR userid='".$user['id']."'";

$db->query("DELETE FROM sessions WHERE ip='".$ip."' OR time<".$time2." ".$qadd);

// Give the user a new one.
$db->query("
INSERT INTO `sessions` ( `id` , `ip` , `time` , `userid` )
VALUES (
'', '".$ip."', '".$time."', '".$user['id']."'
)
");

$res = $db->query("SELECT * FROM sessions");

$session_total = 0;
$session_members = 0;
$session_guests = 0;
while (($session = mysql_fetch_array($res))!==false) {
$sessions[] = $session;
if ($session['userid']==0) {
 $session_guests+=1;
} else if ($session['userid']!=0) {
 $session_members+=1;
}
}

$session_total = $session_guests + $session_members;

?>

here is functions.php

<?php

function get_session_total() {
global $session_total, $session_guests, $session_members;
return $session_total;
}

function get_session_guests() {
global $session_total, $session_guests, $session_members;
return $session_guests;
}

function get_session_members() {
global $session_total, $session_guests, $session_members;
return $session_members;
}

function display_online_users() {

if (get_user_config("name=onlinetime")==-1) {
 return;
}

$t_users = get_session_total();
$t_members = get_session_members();
$t_guests = get_session_guests();

echo "<br />";

if ($t_users!=1) {
 echo "There are <b>".$t_users."</b> users online:<br />";
} else {
 echo "There is <b>".$t_users."</b> user online:<br />";
}

if ($t_members!=1) {
 echo "<b>".$t_members."</b> members, ";
} else {
 echo "<b>".$t_members."</b> member, ";
}

if ($t_guests!=1) {
 echo "<b>".$t_guests."</b> guests.";
} else {
 echo "<b>".$t_guests."</b> guest.";
}
}

function is_online($id) {

global $db;

$id = mysql_escape_string($id);
$result = $db->query("SELECT * FROM sessions WHERE `userid`='".$id."'");

if (mysql_num_rows($result)!=1) {
 return false;
} else {
 return true;
}

}


?>