--- hierarchical_select.module	2011-02-16 23:04:59.000000000 +0300
+++ hierarchical_select.module.New	2011-04-14 01:34:53.000000000 +0400
@@ -328,7 +328,9 @@ function hierarchical_select_json() {
   // Collect all necessary variables.
   $cached = cache_get($hs_form_build_id, 'cache_hierarchical_select');
   $storage = $cached->data;
-
+  if (!$storage) {
+    $storage = $_SESSION['hierarchical_select_js'];
+  }
   // Ensure that the form id in the POST array is the same as the one of the
   // stored parameters of the original form. For 99% of the forms, this step
   // is not necessary, but when a hierarchical_select form item is inside a
@@ -766,6 +768,7 @@ function hierarchical_select_after_build
     $hs_form_build_id = 'hs_form_'. md5(mt_rand());
     $lifetime = variable_get('hierarchical_select_cache_lifetime', HS_CACHE_LIFETIME_DEFAULT);
     cache_set($hs_form_build_id, $storage, 'cache_hierarchical_select', time() + $lifetime);
+    $_SESSION['hierarchical_select_js'] = $storage;
   }
   elseif (isset($_POST['hs_form_build_id'])) {
     // Don't generate a new hs_form_build_id if this is a re-rendering of the