diff --git a/views_natural_sort.module b/views_natural_sort.module
index 8c27b82..7b5ebcf 100644
--- a/views_natural_sort.module
+++ b/views_natural_sort.module
@@ -91,19 +91,42 @@ function views_natural_sort_nodeapi(&$node, $op) {
  * A drupal node object containing at least a nid and title.
  */
 function _views_natural_sort_store_node($node) {
+
+  //TODO: consider using ctools
+  $cache = &_views_natural_sort_get_cache();
+
   $record = new stdClass();
   $record->nid = $node->nid;
   $record->field = 'title';
   $record->content = views_natural_sort_encode($node->title);
+
+  if (empty($cache)) {
+    $cache = array();
+    $result = db_query("SELECT nid, field FROM {views_natural_sort}");
+    while ($row = db_fetch_object($result)) {
+      if (empty($cache[$row->field])) {
+        $cache[$row->field] = array();
+      }
+      $cache[$row->field][] = $row->nid;
+    }
+  }
   // Try to update. On fail, try inserting.
-  $return = drupal_write_record('views_natural_sort', $record, array('nid', 'field'));
-  if (!db_affected_rows()) {
+  if (in_array($record->nid, $cache[$record->field])) {
+    $return = drupal_write_record('views_natural_sort', $record, array('nid', 'field'));
+  }
+  else {
     $return = drupal_write_record('views_natural_sort', $record);
+    $cache[$record->field][] = $record->nid;
   }
-
+  dpm($return);
   return $return;
 }
 
+function _views_natural_sort_get_cache() {
+  static $cache;
+  return $cache;
+}
+
 /**
  * _views_natural_sort_remove_node
  *
@@ -111,7 +134,14 @@ function _views_natural_sort_store_node($node) {
  * A drupal node object containing at least a nid.
  */
 function _views_natural_sort_remove_node($node) {
+  //TODO: consider using ctools
+  $cache = &_views_natural_sort_get_cache();
+  $cache_key = array_search($node->nid, $cache['title']);
+
   db_query('DELETE FROM {views_natural_sort} WHERE nid = %d', $node->nid);
+  if ($cache_key !== FALSE) {
+    unset($cache['title'][$cache_key]);
+  }
 }
 
 /**