diff --git includes/form.inc includes/form.inc
index 15fd33a..ffc7da8 100644
--- includes/form.inc
+++ includes/form.inc
@@ -165,8 +165,6 @@ function drupal_build_form($form_id, &$form_state) {
     $form_state['input'] = $form_state['method'] == 'get' ? $_GET : $_POST;
   }
 
-  $cacheable = FALSE;
-
   if (isset($_SESSION['batch_form_state'])) {
     // We've been redirected here after a batch processing : the form has
     // already been processed, so we grab the post-process $form_state value
@@ -181,7 +179,8 @@ function drupal_build_form($form_id, &$form_state) {
     // form_state data from a previous step, we'll retrieve it so it can
     // be passed on to the form processing code.
     if (isset($form_state['input']['form_id']) && $form_state['input']['form_id'] == $form_id && !empty($form_state['input']['form_build_id'])) {
-      $form = form_get_cache($form_state['input']['form_build_id'], $form_state);
+      $form_build_id = $form_state['input']['form_build_id'];
+      $form = form_get_cache($form_build_id, $form_state);
     }
 
     // If the previous bit of code didn't result in a populated $form
@@ -210,10 +209,9 @@ function drupal_build_form($form_id, &$form_state) {
       }
 
       drupal_prepare_form($form_id, $form, $form_state);
-      // Store a copy of the unprocessed form for caching and indicate that it
-      // is cacheable in case $form_state['cache'] is set.
+      // Store a copy of the unprocessed form to cache in case
+      // $form_state['cache'] is set.
       $original_form = $form;
-      $cacheable = TRUE;
     }
 
     // Now that we know we have a form, we'll process it (validating,
@@ -222,21 +220,6 @@ function drupal_build_form($form_id, &$form_state) {
     // altering the $form_state variable, which is passed into them by
     // reference.
     drupal_process_form($form_id, $form, $form_state);
-
-    // After processing the form, the form builder or a #process callback may
-    // have set $form_state['cache'] to indicate that the original form and the
-    // $form_state shall be cached. But the form may only be cached if the
-    // special 'no_cache' property is not set to TRUE.
-    if (!empty($form_state['cache']) && empty($form_state['no_cache'])) {
-      // Cache the form upon initial build of the form.
-      if ($cacheable) {
-        form_set_cache($form_build_id, $original_form, $form_state);
-      }
-      // After processing a cached form, only update the cached form state.
-      else {
-        form_set_cache($form_state['input']['form_build_id'], NULL, $form_state);
-      }
-    }
   }
 
   // Most simple, single-step forms will be finished by this point --
@@ -254,6 +237,20 @@ function drupal_build_form($form_id, &$form_state) {
   if ($form_state['rebuild'] && $form_state['submitted'] && !form_get_errors()) {
     $form = drupal_rebuild_form($form_id, $form_state);
   }
+  // After processing the form, the form builder or a #process callback may
+  // have set $form_state['cache'] to indicate that the original form and the
+  // $form_state shall be cached. But the form may only be cached if the
+  // special 'no_cache' property is not set to TRUE and we are not rebuilding.
+  elseif ($form_state['cache'] && empty($form_state['no_cache'])) {
+    // Cache the original, unprocessed form upon initial build of the form.
+    if (isset($original_form)) {
+      form_set_cache($form_build_id, $original_form, $form_state);
+    }
+    // After processing a cached form, only update the cached form state.
+    else {
+      form_set_cache($form_build_id, NULL, $form_state);
+    }
+  }
 
   // Don't override #theme if someone already set it.
   if (!isset($form['#theme'])) {