Programmatic Setting of Item's setSpecialPrice Doesn't Stick - magento

Question

I'm trying to programmaticly add an item to the visitor's shopping cart. In the process, the item is given a custom price. On the page initially displayed after item addition, the "My Cart" summary (in the right column) indicates that the cart contains an item with the correct price. However, when I go to the view cart page, the item is listed with its default price (instead of the custom price).
How do I make the custom price stick?
Thank you,
Ben
Here's the code:
$product = Mage::getModel('catalog/product');
$product->load(169);
$product->setSpecialPrice(10);
$cart = Mage::getSingleton('checkout/cart');
$cart->addProduct($product, array('qty' => 1, 'options' => array(5 => 'spec goes here' . time())));
$cart->save();
I tried calling $product->save() after $product->setSpecialPrice() but that resulted in:
Warning: Invalid argument supplied for foreach() in app\code\core\Mage\Eav\Model\Entity\Abstract.php on line 1068
#0 app\code\core\Mage\Eav\Model\Entity\Abstract.php(1068): mageCoreErrorHandler(2, 'Invalid argumen...', 'C:\Program File...', 1068, Array)
#1 app\code\core\Mage\Eav\Model\Entity\Abstract.php(1012): Mage_Eav_Model_Entity_Abstract->_collectSaveData(Object(Mage_Catalog_Model_Product))
#2 app\code\core\Mage\Core\Model\Abstract.php(318): Mage_Eav_Model_Entity_Abstract->save(Object(Mage_Catalog_Model_Product))
#3 app\code\local\BenGribaudo\RazaOrderGrid\controllers\IndexController.php(13): Mage_Core_Model_Abstract->save()
#4 app\code\core\Mage\Core\Controller\Varien\Action.php(418): BenGribaudo_RazaOrderGrid_IndexController->addAction()
#5 app\code\core\Mage\Core\Controller\Varien\Router\Standard.php(253): Mage_Core_Controller_Varien_Action->dispatch('add')
#6 app\code\core\Mage\Core\Controller\Varien\Front.php(176): Mage_Core_Controller_Varien_Router_Standard->match(Object(Mage_Core_Controller_Request_Http))
#7 app\code\core\Mage\Core\Model\App.php(340): Mage_Core_Controller_Varien_Front->dispatch()
#8 app\Mage.php(627): Mage_Core_Model_App->run(Array)
#9 index.php(80): Mage::run('', 'store')
#10 {main}

Answer 1

Set Special Price Programatically In Magento