Trata asi:
Código PHP:
<?php
set_time_limit(0);
session_name("upload");
session_start();
if(isset($_GET['d']))
$_SESSION['distribuidor'] = intval($_GET['d']);
else if(!isset($_SESSION['distribuidor']))
$_SESSION['distribuidor'] = 0;
if(isset($_POST['login']))
{
include("functions/validar.php");
include("functions/mysql.php");
mysql_conectar();
$_POST['email'] = DividirCorreo(LimpiarCorreo($_POST['email']));
$_POST['password'] = md5(md5($_POST['password']));
$sql = "SELECT id FROM usuarios WHERE mail-user = \"{$_POST['email']['usuario']}\" AND email-domain = \"{$_POST['email']['dominio']}\" AND passwd = \"{$_POST['password']}\" limit 1");
$resultado = mysql_query($sql);
if( mysql_num_rows($resultado) == 1 )
{