Collection.php

<?php
class Module_Sales_Model_Resource_Quote_Item_Collection extends
    Mage_Sales_Model_Resource_Quote_Item_Collection{
    /**
     * Add products to items and item options
     *
     * @return Mage_Sales_Model_Resource_Quote_Item_Collection
     */
    protected function _assignProducts()
    {
        parent::_assignProducts();
        foreach($this->getItemsByColumnValue('product_type', 'configurable') as $item){
            if(!$this->getItemByColumnValue('parent_item_id', $item->getId())){
                if($option = $item->getOptionByCode('info_buyRequest')){
                    $buyRequest = new Varien_Object(unserialize($option->getValue()));
                    $buyRequest->unsetData('reset_count');
                    try{
                        $this->_quote->updateItem((int)$item->getId(), $buyRequest);
                    }
                    catch(Exception $e){
                        // product out of stock
                    }
                }
            }
        }
        return $this;
    }
}