url amigaveis

tem algum erro nesse codigo aqui ? a pagina ta retornando para 404.php sendo que a url existe e ta tudo certinho no banco.

E diz :

Notice: Undefined offset: 1 in

pagina categoria.php

<?php
$catUrl = mysql_real_escape_string($url[1]);
$readCat = read('up_cat',"WHERE url = '$catUrl'");
if(!$readCat){
header('Location: '.BASE.'/404' );

foreach($readCat as $cat);
setViews($cat['id']);
?>

pagina getSis.php

function getHome(){
//$url = $_GET['url'];
//$url = isset($_GET['url']) ? $_GET['url'] : '<no url set>';
$url = isset($_GET['url']) ;
$url = explode('/', $url);
$url[0] = ($url[0] == NULL ? 'index' : $url[0]);

	if(file_exists('tpl/'.$url[0].'.php')){
 require_once('tpl/'.$url[0].'.php');
	}elseif(file_exists('tpl/'.$url[0].'/'.$url[1].'.php')){
 require_once('tpl/'.$url[0].'/'.$url[1].'.php');
	}else{
 require_once('tpl/404.php');
	}
}