STRANGE...Not able to get cart items in magento on a custom page (only when the customer is logged in) - magento

Question

Here is the standard code I am using for getting cart items and their attributes which works only when the customer is not logged in. As soon as I log in using my account this script stops working and does not return the items in the cart. Also the cart items count is also 0. But as soon as I close the browser(session ends..) and the script returns the cartitems correctly! Very strange, I have not been able to find out the cause. Please guide, anyone?
require_once('../app/Mage.php') ;
umask(0);
Mage::app();
Mage::getSingleton('core/session', array('name'=>'frontend'));
$session = Mage::getSingleton('checkout/session');
$items = $session->getQuote()->getAllVisibleItems();
foreach ($items as $item) {
//$canProceed=0;
echo $productname = $item->getName(); //HERE IS THE COMPLETE CODE:<?php
ini_set('display_errors',true);
require_once('../app/Mage.php') ;
Mage::setIsDeveloperMode(true);
umask(0);
Mage::app();
//Getting buyer's country label
$bcountry1 = $_REQUEST['country']; //gets country code
$_countries = Mage::getResourceModel('directory/country_collection')
->loadData()
->toOptionArray(false);
foreach($_countries as $_country){
if ($_country['value']==$bcountry1){$bcountry = $_country['label'];}
}
//Fetching vendor for each product
$config = Mage::getConfig()->getResourceConnectionConfig("default_setup");
$dbinfo = array("host" => $config->host,
"user" => $config->username,
"pass" => $config->password,
"dbname" => $config->dbname );
$hostname = $dbinfo["host"];
$user2 = $dbinfo["user"];
$password = $dbinfo["pass"];
$dbname = $dbinfo["dbname"];
$dbhandle = mysql_connect($hostname,$user2,$password) or die("Unable to connect");
$selected = mysql_select_db("myart2",$dbhandle);
$Proceed=0;
//Getting all products in the cart
//echo $cart = Mage::getSingleton('checkout/cart')->getItemsCount();
// Secret Sauce - Initializes the Session for the FRONTEND
// Magento uses different sessions for 'frontend' and 'adminhtml'
Mage::getSingleton('core/session', array('name'=>'frontend'));
$session = Mage::getSingleton('checkout/session');
$items = $session->getQuote()->getAllVisibleItems();
foreach ($items as $item) {
//$canProceed=0;
$productname = $item->getName();
$product = Mage::getModel('catalog/product')->loadByAttribute('sku', $item->getSku(), array('manufacturer'));
$manufacturer = $product->getResource()->getAttribute('manufacturer')->getFrontEnd()->getValue($product);
$qry="select * from vendors WHERE company_name='$manufacturer'";
$result = mysql_query($qry) or die("Unable to run select query");
$row = mysql_fetch_array($result) or die("Unable to fetch data");
if( strcasecmp($row['country'],$bcountry)!=0 && $row['ships_abroad']!=1)
{$Proceed=1;$productnames[]=$productname;}
}
if($Proceed==1)
{
echo implode(',',$productnames);
}
else {echo 1; }
?>

Answer 1

I've tested the following four main permutations, and the code works in a stock CE1.7 instance in all cases:
Create guest quote
Convert guest quote to customer quote via login
Instantiate existing customer quote via login
Merge guest quote with customer quote via login
Adjust the server & app environment params as follows to view & rule out any errors (edit - added complete script; note the closing "}"):
<?php
error_reporting(E_ALL | E_STRICT);
ini_set('display_errors',true);
require_once('../app/Mage.php') ;
Mage::setIsDeveloperMode(true);
umask(0);
Mage::app();
$session = Mage::getSingleton('checkout/session');
$items = $session->getQuote()->getAllVisibleItems();
foreach ($items as $item) {
//$canProceed=0;
echo $productname = $item->getName();
}