diff --git a/hierarchical_select.js b/hierarchical_select.js
index 059fcc8..4d3ae1f 100644
--- a/hierarchical_select.js
+++ b/hierarchical_select.js
@@ -471,7 +471,14 @@ Drupal.HierarchicalSelect.update = function(hsid, updateType, settings) {
   switch (updateType) {
     case 'update-hierarchical-select':
       var value = $('#'+ settings.select_id).val();
-      var lastUnchanged = parseInt(settings.select_id.replace(/^.*-hierarchical-select-selects-(\d+)$/, "$1")) + 1;
+
+      if (settings.select_id.substring(settings.select_id.length - 3, settings.select_id.length - 1) == '--') {
+        var lastUnchanged = parseInt(settings.select_id.replace(/^.*-hierarchical-select-selects-(\d+)--.$/, "$1")) + 1;
+      }
+      else {
+        var lastUnchanged = parseInt(settings.select_id.replace(/^.*-hierarchical-select-selects-(\d+)$/, "$1")) + 1;
+      }
+
       var optionClass = $('#'+ settings.select_id).find('option[value='+ value +']').attr('class');
 
       // Don't do anything (also no callback to the server!) when the selected
diff --git a/hierarchical_select.module b/hierarchical_select.module
index 731267d..0689e8a 100644
--- a/hierarchical_select.module
+++ b/hierarchical_select.module
@@ -349,11 +349,11 @@ function _hs_process_determine_hsid($element, &$form_state) {
   // generate a new one based on the last HSID used (which is
   // stored in form state storage).
   if (!isset($element['#value']) || !is_array($element['#value']) || !array_key_exists('hsid', $element['#value'])) {
-    if (!isset($form_state['storage']['hs']['last_hsid'])) {
-      $form_state['storage']['hs']['last_hsid'] = -1;
+    if (!isset($_SESSION['storage']['hs']['last_hsid'])) {
+      $_SESSION['storage']['hs']['last_hsid'] = -1;
     }
-    $form_state['storage']['hs']['last_hsid']++;
-    $hsid = $form_state['storage']['hs']['last_hsid'];
+    $_SESSION['storage']['hs']['last_hsid']++;
+    $hsid = $_SESSION['storage']['hs']['last_hsid'];
   }
   else {
     $hsid = check_plain($element['#value']['hsid']);
@@ -1784,6 +1784,13 @@ function _hierarchical_select_hierarchy_generate($config, $selection, $required,
         $hierarchy->levels[$depth] = array('label_' . $depth => $label) + $hierarchy->levels[$depth] + $children;
 
         $hierarchy->levels[$depth] = _hierarchical_select_apply_entity_settings($hierarchy->levels[$depth], $config);
+
+        // Remove the level if it no longer has any children. This is possible
+        // if _hierarchical_select_apply_entity_settings removes the terms
+        // because they have no entities.
+        if (count($hierarchy->levels[$depth]) <= 1) {
+          unset($hierarchy->levels[$depth]);
+        }
       }
     }
   }
@@ -1856,6 +1863,9 @@ function _hierarchical_select_apply_entity_settings($level, $config) {
     $special_items['exclusive'] = array_keys(array_filter($config['special_items'], '_hierarchical_select_special_item_exclusive'));
     $special_items['none']      = array_keys(array_filter($config['special_items'], '_hierarchical_select_special_item_none'));
   }
+  else {
+    $special_items = array();
+  }
 
   // Only do something when the entity_count or the require_entity (or both)
   // settings are enabled.
diff --git a/modules/hs_taxonomy.module b/modules/hs_taxonomy.module
index 2fc3fb4..76fcdf9 100644
--- a/modules/hs_taxonomy.module
+++ b/modules/hs_taxonomy.module
@@ -625,6 +625,18 @@ function hs_taxonomy_hierarchical_select_children($parent, $params) {
     }
   }
 
+  // If the term has no nodes associated with it, and it has no child terms,
+  // remove it.
+  foreach ($terms as $key => $term) {
+    $count = hs_taxonomy_hierarchical_select_entity_count($term->tid, array());
+    if ($count == 0) {
+      $children = taxonomy_get_children($term->tid);
+      if(empty($children)) {
+        unset($terms[$key]);
+      }
+    }
+  }
+
   return _hs_taxonomy_hierarchical_select_terms_to_options($terms);
 }
 
@@ -749,22 +761,18 @@ function hs_taxonomy_hierarchical_select_create_item($label, $parent, $params) {
   }
 }
 
-
 /**
  * Implementation of hook_hierarchical_select_entity_count().
  */
-/*
-// TODO: port this to D7.
 function hs_taxonomy_hierarchical_select_entity_count($item, $params) {
   // Allow restricting entity count by node type.
-  if ($params['entity_count_for_node_type']) {
+  if (isset($params['entity_count_for_node_type'])) {
     return hs_taxonomy_term_count_nodes($item, $params['entity_count_for_node_type']);
   }
   else {
     return hs_taxonomy_term_count_nodes($item);
   }
 }
-*/
 
 /**
  * Implementation of hook_hierarchical_select_implementation_info().
@@ -1040,8 +1048,7 @@ function _hs_taxonomy_hierarchical_select_get_tree($vid, $parent = 0, $depth = -
 }
 
 /**
- * Drupal core's taxonomy_term_count_nodes() is buggy. See
- * http://drupal.org/node/144969#comment-843000.
+ * Count the number of nodes assigned to a term, or its children terms.
  */
 function hs_taxonomy_term_count_nodes($tid, $type = 0) {
   static $count;
@@ -1055,14 +1062,19 @@ function hs_taxonomy_term_count_nodes($tid, $type = 0) {
   }
 
   if (!isset($count[$type][$tid])) {
-    if (is_numeric($type)) {
-      // TODO Please convert this statement to the D7 database API syntax.
-      $count[$type][$tid] = db_query(db_rewrite_sql("SELECT COUNT(DISTINCT(n.nid)) AS count FROM {taxonomy_term_node} t INNER JOIN {node} n ON t.nid = n.nid WHERE n.status = 1 AND t.tid IN (%s)"), implode(',', $tids))->fetchField();
-    }
-    else {
-      // TODO Please convert this statement to the D7 database API syntax.
-      $count[$type][$tid] = db_query(db_rewrite_sql("SELECT COUNT(DISTINCT(n.nid)) AS count FROM {taxonomy_term_node} t INNER JOIN {node} n ON t.nid = n.nid WHERE n.status = 1 AND n.type = '%s' AND t.tid IN (%s)"), $type, implode(',', $tids))->fetchField();
+    $query = db_select('taxonomy_index', 't');
+    $query->innerJoin('node', 'n', '(t.nid = n.nid)');
+    $query->fields('n', array('nid'));
+    $query->condition('n.status', 1, '=');
+    $query->condition('t.tid', implode(',', $tids));
+    $query->distinct(TRUE);
+
+    if (!is_numeric($type)) {
+      $query->condition('n.type', $type, "=");
     }
+
+    $query->execute();
+    $count[$type][$tid] = $query->countQuery()->execute()->fetchField();
   }
   return $count[$type][$tid];
 }