Product collection shows out of stock configurable products

Question

I made this query to show related products by Manufacturer.

It works perfectly with simple products, but it shows configurable products that are not available.

I would like to show only available configurable products in that list.

$manu = $product->getManufacturer();
            $brand_name = $product->getAttributeText('manufacturer');
            $brand = Mage::getSingleton('catalog/product')
                ->getCollection()
                ->addAttributeToSelect('*')
                ->addAttributeToFilter('visibility', array(
                    Mage_Catalog_Model_Product_Visibility::VISIBILITY_BOTH,
                    Mage_Catalog_Model_Product_Visibility::VISIBILITY_IN_CATALOG
                ))
                ->addAttributeToFilter('manufacturer', $manu)
                ->addAttributeToFilter('is_in_stock', 1)
                ->addAttributeToFilter('qty', array("gt" => 0))
                ->addAttributeToFilter('status', 1)
                ->setOrder('updated_at','DESC')
                ->setPageSize(5);
            Mage::getModel('cataloginventory/stock')->addInStockFilterToCollection($brand);


            if ($product) {
                $brand->addAttributeToFilter('entity_id', array(
                        'neq' => Mage::registry('current_product')->getId())
                );
            }

Answer 1

They are likely filtered out as the stock is not maintained on the configureable product level but on simple products level, ->addAttributeToFilter('qty', array("gt" => 0)) filters out such products. The solution would be to check if the following condition is true: $product->isSalable()