Unable to load quote object

Set the store first:

$store = Mage::getSingleton('core/store')->load(1);

$quote = Mage::getModel('sales/quote')->setStore($store)->load($quoteId);

Nope, Mage_Sales_Model_Quote is like all the other db based models. You make something wrong. Maybe hardcode the $quoteId? Are you sure it is correct? Both codes should work.