diff --git a/wp-admin/admin.php b/wp-admin/admin.php
index 7cf746f9d..777873512 100644
--- a/wp-admin/admin.php
+++ b/wp-admin/admin.php
@@ -8,10 +8,7 @@ header('Last-Modified: ' . gmdate('D, d M Y H:i:s') . ' GMT');
 header('Cache-Control: no-cache, must-revalidate, max-age=0');
 header('Pragma: no-cache');
 
-$dogs = $wpdb->get_results("SELECT * FROM $wpdb->categories");
-foreach ($dogs as $catt) {
-	$cache_categories[$catt->cat_ID] = $catt;
-}
+update_category_cache();
 
 get_currentuserinfo();
 
diff --git a/wp-includes/functions.php b/wp-includes/functions.php
index d8fde6af9..d1083787c 100644
--- a/wp-includes/functions.php
+++ b/wp-includes/functions.php
@@ -615,6 +615,9 @@ function &get_page(&$page, $output = OBJECT) {
 function &get_category(&$category, $output = OBJECT) {
 	global $cache_categories, $wpdb;
 
+	if ( ! isset($cache_categories))
+		update_category_cache();
+
 	if (is_object($category)) {
 		if ( ! isset($cache_categories[$category->cat_ID]))
 			$cache_categories[$category->cat_ID] = &$category;
@@ -1170,6 +1173,9 @@ function update_post_category_cache($post_ids) {
 	post_id, category_id FROM $wpdb->categories, $wpdb->post2cat
 	WHERE category_id = cat_ID AND post_id IN ($post_ids)");
 
+	if (! isset($cache_categories))
+		update_category_cache();
+		
 	if ( !empty($dogs) ) {
 		foreach ($dogs as $catt) {
 			$category_cache[$catt->post_id][$catt->category_id] = &$cache_categories[$catt->category_id];