diff --git a/entityreference_prepopulate.module b/entityreference_prepopulate.module
index b6346c6..2747ee4 100644
--- a/entityreference_prepopulate.module
+++ b/entityreference_prepopulate.module
@@ -128,7 +128,14 @@ function entityreference_prepopulate_field_attach_form($entity_type, $entity, &$
       }
 
       $field = $value['field'];
-      if (entityreference_prepopulate_get_values($field, $instance) || ($id && !empty($settings['action_on_edit']))) {
+
+      // Store prepopulated values in the form state to make them persistent,
+      // in case the form is rebuilt by AJAX requests.
+      if ($values = entityreference_prepopulate_get_values($field, $instance)) {
+        $form_state['entityreference_prepopulate'][$instance['entity_type']][$instance['bundle']][$field['field_name']] = $values;
+      }
+
+      if ($values || ($id && !empty($settings['action_on_edit']))) {
         // New entity with prepopualte values, or an existing entity,
         // we might need to disable/ hide the group-audience field.
         if ($settings['action'] == 'disable') {
@@ -249,17 +256,24 @@ function entityreference_prepopulate_get_values_from_url($field, $instance, $fla
   if (isset($cache[$identifier])) {
     return $cache[$identifier];
   }
-  $cache[$identifier] = FALSE;
 
-  if (empty($_GET[$field_name]) || !is_string($_GET[$field_name])) {
-    return;
+  // Check to see if we cached the values in a $form_state object (and we are
+  // refreshing the form)
+  $form_build_id = isset($_GET['form_build_id']) ? $_GET['form_build_id'] : isset($_POST['form_build_id']) ? $_POST['form_build_id'] : NULL;
+  if (!empty($form_build_id)) {
+    $form_state = array();
+    $form = form_get_cache($form_build_id, $form_state);
+    if (isset($form_state['entityreference_prepopulate'][$instance['entity_type']][$instance['bundle']][$field_name])) {
+      $ids = $form_state['entityreference_prepopulate'][$instance['entity_type']][$instance['bundle']][$field_name];
+    }
   }
-
-  if (empty($instance['settings']['behaviors']['prepopulate']['status'])) {
+  elseif (empty($_GET[$field_name]) || !is_string($_GET[$field_name]) || empty($instance['settings']['behaviors']['prepopulate']['status'])) {
+    $cache[$identifier] = FALSE;
     return;
   }
-
-  $ids = explode(',', $_GET[$field_name]);
+  else {
+    $ids = explode(',', $_GET[$field_name]);
+  }
 
   // Check if the IDs are valid, and get filter out the ones that are not valid.
   $handler = entityreference_get_selection_handler($field, $instance);