diff --git a/classes/catalogue.class.php b/classes/catalogue.class.php
index 8099c5ec7..307ecca07 100755
--- a/classes/catalogue.class.php
+++ b/classes/catalogue.class.php
@@ -547,10 +547,12 @@ public function displayProductOptions($product_id = null, $selected_options_arra
 	 * @return array
 	 */
 	public function displaySort($search = false) {
-		
+		// Default sort order
+		$default = array('field'=>$GLOBALS['config']->get('config', 'product_sort_column'), 'sort'=>$GLOBALS['config']->get('config', 'product_sort_direction'));
 		// Sort
 		if ($search || $this->_sort_by_relevance) {
 			$sorters['Relevance'] = $GLOBALS['language']->common['relevance'];
+			$default['field'] = 'Relevance'; // default search order is always 'Relevance'
 		}
 		$sorters['name']  = $GLOBALS['language']->common['name'];
 		$sorters['date_added'] = $GLOBALS['language']->category['sort_date'];
@@ -573,7 +575,7 @@ public function displaySort($search = false) {
 				$direction = (isset($GLOBALS['language']->category[strtolower('sort_'.$field.'_'.$order)])) ? $GLOBALS['language']->category[strtolower('sort_'.$field.'_'.$order)] : $direction;
 				$assign = array('name' => $name, 'field' => $field, 'order' => $order, 'direction' => $direction);
 
-				if ((isset($_GET['sort'][$field]) && strtoupper($_GET['sort'][$field]) == $order)  || (!isset($_GET['sort']) && $field==$GLOBALS['config']->get('config', 'product_sort_column') && $order==$GLOBALS['config']->get('config', 'product_sort_direction'))) {
+				if ((isset($_GET['sort'][$field]) && strtoupper($_GET['sort'][$field]) == $order) || (!isset($_GET['sort']) && $field == $default['field'] && $order == $default['sort'])) {
 					$assign['selected'] = 'selected="selected"';
 				} else {
 					$assign['selected'] = '';
@@ -1539,7 +1541,7 @@ public function searchCatalogue($search_data = null, $page = 1, $per_page = 10,
 				if (!empty($search_data['priceMin']) && is_numeric($search_data['priceMin'])) {
 					$price = round($GLOBALS['tax']->priceConvertFX($search_data['priceMin'])/1.05, 3);
 					if ($sale_mode == 1) {
-						$where[] = 'IF (G.sale_price IS NULL, IF (I.sale_price = 0, I.price, I.sale_price) >= '.$price.', IF (G.sale_price = 0, G.price, G.sale_price) >= '.$price.')';
+						$where[] = 'IF (G.product_id IS NULL, IF (I.sale_price IS NULL OR I.sale_price = 0, I.price, I.sale_price) >= '.$price.', IF (G.sale_price IS NULL OR G.sale_price = 0, G.price, G.sale_price) >= '.$price.')';
 					} else if ($sale_mode == 2) {
 							$where[] = 'IF (G.price IS NULL, (I.price - ((I.price / 100) * '.$sale_percentage.')) >= '.$price.', (G.price - ((G.price / 100) * '.$sale_percentage.')) >= '.$price.')';
 						} else {
@@ -1550,7 +1552,7 @@ public function searchCatalogue($search_data = null, $page = 1, $per_page = 10,
 				if (!empty($search_data['priceMax']) && is_numeric($search_data['priceMax'])) {
 					$price = round($GLOBALS['tax']->priceConvertFX($search_data['priceMax'])*1.05, 3);
 					if ($sale_mode == 1) {
-						$where[] = 'IF (G.sale_price IS NULL, IF (I.sale_price = 0, I.price, I.sale_price) <= '.$price.', IF (G.sale_price = 0, G.price, G.sale_price) <= '.$price.')';
+						$where[] = 'IF (G.product_id IS NULL, IF (I.sale_price IS NULL OR I.sale_price = 0, I.price, I.sale_price) <= '.$price.', IF (G.sale_price IS NULL OR G.sale_price = 0, G.price, G.sale_price) <= '.$price.')';
 					} else if ($sale_mode == 2) {
 							$where[] = 'IF (G.price IS NULL, (I.price - ((I.price / 100) * '.$sale_percentage.')) <= '.$price.', (G.price - ((G.price / 100) * '.$sale_percentage.')) <= '.$price.')';
 						} else {
@@ -1564,7 +1566,7 @@ public function searchCatalogue($search_data = null, $page = 1, $per_page = 10,
 					$search_data['priceMax'] == $search_data['priceMin']) {
 					$price = round($GLOBALS['tax']->priceConvertFX($search_data['priceMin']), 3);
 					if ($sale_mode == 1) {
-						$where[] = 'IF (G.sale_price IS NULL, IF (I.sale_price = 0, I.price, I.sale_price) = '.$price.', IF (G.sale_price = 0, G.price, G.sale_price) = '.$price.')';
+						$where[] = 'IF (G.product_id IS NULL, IF (I.sale_price IS NULL OR I.sale_price = 0, I.price, I.sale_price) = '.$price.', IF (G..sale_price IS NULL OR G.sale_price = 0, G.price, G.sale_price) = '.$price.')';
 					} else if ($sale_mode == 2) {
 							$where[] = 'IF (G.price IS NULL, (I.price - ((I.price / 100) * '.$sale_percentage.')) = '.$price.', (G.price - ((G.price / 100) * '.$sale_percentage.')) = '.$price.')';
 						} else {
@@ -1574,7 +1576,7 @@ public function searchCatalogue($search_data = null, $page = 1, $per_page = 10,
 					if (!empty($search_data['priceMin']) && is_numeric($search_data['priceMin'])) {
 						$price = round($GLOBALS['tax']->priceConvertFX($search_data['priceMin']), 3);
 						if ($sale_mode == 1) {
-							$where[] = 'IF (G.sale_price IS NULL, IF (I.sale_price = 0, I.price, I.sale_price) >= '.$price.', IF (G.sale_price = 0, G.price, G.sale_price) >= '.$price.')';
+							$where[] = 'IF (G.product_id IS NULL, IF (I.sale_price = 0, I.price, I.sale_price) >= '.$price.', IF (G.sale_price = 0, G.price, G.sale_price) >= '.$price.')';
 						} else if ($sale_mode == 2) {
 								$where[] = 'IF (G.price IS NULL, (I.price - ((I.price / 100) * '.$sale_percentage.')) >= '.$price.', (G.price - ((G.price / 100) * '.$sale_percentage.')) >= '.$price.')';
 							} else {
@@ -1584,7 +1586,7 @@ public function searchCatalogue($search_data = null, $page = 1, $per_page = 10,
 					if (!empty($search_data['priceMax']) && is_numeric($search_data['priceMax'])) {
 						$price = round($GLOBALS['tax']->priceConvertFX($search_data['priceMax']), 3);
 						if ($sale_mode == 1) {
-							$where[] = 'IF (G.sale_price IS NULL, IF (I.sale_price = 0, I.price, I.sale_price) <= '.$price.', IF (G.sale_price = 0, G.price, G.sale_price) <= '.$price.')';
+							$where[] = 'IF (G.product_id IS NULL, IF (I.sale_price IS NULL OR I.sale_price = 0, I.price, I.sale_price) <= '.$price.', IF (G.sale_price IS NULL OR G.sale_price = 0, G.price, G.sale_price) <= '.$price.')';
 						} else if ($sale_mode == 2) {
 								$where[] = 'IF (G.price IS NULL, (I.price - ((I.price / 100) * '.$sale_percentage.')) <= '.$price.', (G.price - ((G.price / 100) * '.$sale_percentage.')) <= '.$price.')';
 							} else {
@@ -1599,14 +1601,15 @@ public function searchCatalogue($search_data = null, $page = 1, $per_page = 10,
 				//    $where[] = 'I.manufacturer IN ('.implode(',', '\''.$search_data['manufacturer']).'\')';
 			}
 
+			$order = array();
 			if (isset($_GET['sort']) && is_array($_GET['sort'])) {
 				foreach ($_GET['sort'] as $field => $direction) {
 					$order['field'] = $field;
 					if ($field == 'price') {
 						if ($sale_mode == 1) {
-							$order['field'] = 'IF (G.sale_price IS NULL, IF (I.sale_price = 0, I.price, I.sale_price), IF (G.sale_price = 0, G.price, G.sale_price))';
+							$order['field'] = 'IF (G.product_id IS NULL, IF (I.sale_price IS NULL OR I.sale_price = 0, I.price, I.sale_price), IF (G.sale_price IS NULL OR G.sale_price = 0, G.price, G.sale_price))';
 						} else {
-							$order['field'] = 'IF (G.price IS NULL, I.price, G.price)';
+							$order['field'] = 'IFNULL (G.price, I.price)';
 						}
 					}
 					$order['sort'] = (strtolower($direction) == 'asc') ? 'ASC' : 'DESC';
@@ -1616,11 +1619,19 @@ public function searchCatalogue($search_data = null, $page = 1, $per_page = 10,
 				$order['field'] = 'Relevance';
 				$order['sort'] = 'DESC';
 			}
+			// Use store settings for sort order if none designated
+			if (empty($order)) {
+				$order['field'] = $GLOBALS['config']->get('config', 'product_sort_column');
+				$order['sort'] = $GLOBALS['config']->get('config', 'product_sort_direction');
+				if (empty($order['field']) || empty($order['sort'])) {
+					unset($order); // store settings were somehow invalid
+				}
+			}
 			if (empty($search_data['keywords']) && $order['field'] == 'Relevance') {
 				if ($sale_mode == 1) {
-					$order['field'] = 'IF (G.sale_price IS NULL, IF (I.sale_price = 0, I.price, I.sale_price), IF (G.sale_price = 0, G.price, G.sale_price))';
+					$order['field'] = 'IF (G.product_id IS NULL, IF (I.sale_price IS NULL OR I.sale_price = 0, I.price, I.sale_price), IF (G.sale_price IS NULL OR G.sale_price = 0, G.price, G.sale_price))';
 				} else {
-					$order['field'] = 'IF (G.price IS NULL, I.price, G.price)';
+					$order['field'] = 'IFNULL (G.price, I.price)';
 				}
 			}
 			if (is_array($order)) {