Your cookie information is wrong. It should be:
function SetCookieInfo($theCookieString) {
$numDays = 99999;
$theDomain = ".promocaototal.pt";
$thePath = "/";
$cookSec = false;
if ($numDays == "") $numDays="0";
$theDate = strtotime("+".$numDays." Days");
setcookie($this->CartName."_Items", $theCookieString, $theDate, $thePath, $theDomain, $cookSec);
}