diff --git a/serial.inc b/serial.inc
index 917149f..ecf9a69 100644
--- a/serial.inc
+++ b/serial.inc
@@ -114,16 +114,16 @@ function _serial_get_table_schema() {
         'not null' => TRUE,
         'description' => 'The atomic serial field.',
       ),
-      'nid' => array(
-        'type' => 'int',
-        'unsigned' => TRUE,
+      'uniqid' => array(
+        'description' => 'Unique temporary allocation Id.',
+        'type' => 'varchar',
+        'length' => 23,
         'not null' => TRUE,
-        'description' => 'Id of the owner node.',
-      ),
+        'default' => ''),
     ),
     'primary key' => array('sid'),
     'unique keys' => array(
-      'nid' => array('nid'),
+      'uniqid' => array('uniqid'),
     ),
   );
 }
@@ -142,29 +142,30 @@ function _serial_get_table_schema() {
  * @return
  *   the unique serial value number.
  */
-function _serial_generate_value($nid, $bundle, $field_name, $delete = TRUE) {
+function _serial_generate_value($bundle, $field_name, $delete = TRUE) {
 
   // Get the name of the relevant table.
   $table = _serial_get_table_name($bundle, $field_name);
 
-  // Create a temporary record for this node and retrieve the serial value.
+  // Insert a temporary record to get a new unique serial value.
+  $uniqid = uniqid('', TRUE);
   $sid = db_insert($table)
     ->fields(array(
-      'nid' => $nid,
+      'uniqid' => $uniqid,
     ))
     ->execute();
 
   // If there's a reason why it's come back undefined, reset it.
   $sid = isset($sid) ? $sid : 0;
 
-  // Delete old temporary records:
+  // Delete the temporary record.
   if ($delete && ($sid % 10) == 0) {
-    db_delete($table)
-      ->condition('nid', $nid, '<')
-      ->execute();
+  db_delete($table)
+    ->condition('uniqid', $uniqid, '=')
+    ->execute();
   }
 
-  // Return the new unique serial value:
+  // Return the new unique serial value.
   return $sid;
 }
 
@@ -189,22 +190,27 @@ function _serial_init_old_nodes($bundle, $field_name) {
   foreach ($result as $node) {
     $nid = $node->nid;
     $node = node_load($nid);
-    $sid = _serial_generate_value($nid, $bundle, $field_name, FALSE);
+    $sid = _serial_generate_value($bundle, $field_name, FALSE);
     $node->{$field_name} = array('und' => array(array('value' => $sid)));
     node_save($node);
-    $last_nid = $nid;
     $count++;
   }
 
-  // Delete temporary records (except the last):
-  if (isset($last_nid)) {
-    $serial_table = _serial_get_table_name($bundle, $field_name);
-    db_delete($serial_table)
-      ->condition('nid', $last_nid, '<')
-      ->execute();
-  }
-
   // Return the number of existing nodes that have been initialized:
   return $count;
 }
 
+/**
+ * Retrieves all the managed serial fields.
+ *
+ * @return result set containing pairs of (node type name, field name).
+ */
+function _serial_get_all_fields() {
+  $query = db_select('field_config', 'f');
+  $query->join('field_config_instance', 'i', 'i.field_name = f.field_name');
+  $query->fields('i', array('bundle', 'field_name'))
+        ->condition('f.type', 'serial', '=')
+        ->condition('i.deleted', 0, '=');
+  $result = $query->execute();
+  return $result->fetchAll();
+}
\ No newline at end of file
diff --git a/serial.install b/serial.install
index b555dce..55359c2 100644
--- a/serial.install
+++ b/serial.install
@@ -6,7 +6,7 @@
  */
 
 /**
- * Implementation of hook_uninstall().
+ * Implements hook_uninstall().
  */
 function serial_uninstall() {
   /*
@@ -37,7 +37,7 @@ function serial_field_schema($field) {
 }
 
 /**
- * Implementation of hook_schema().
+ * Implements hook_schema().
  */
 function serial_schema() {
   // Get the standard schema:
@@ -46,10 +46,7 @@ function serial_schema() {
 
   // Build the schema by iteration over all the serial field instances:
   $schema = array();
-  $query = "SELECT i.bundle AS bundle, f.field_name AS field_name ".
-           "FROM {field_config} f, {field_config_instance} i ".
-           "WHERE f.field_name = i.field_name AND f.type = 'serial' AND i.deleted = 0";
-  $result = db_query($query);
+  $result = _serial_get_all_fields();
   foreach ($result as $field) {
     $table = _serial_get_table_name($field->bundle, $field->field_name);
     $schema[$table] = $table_schema;
@@ -59,3 +56,30 @@ function serial_schema() {
   return $schema;
 }
 
+/**
+ * Upgrade path.
+ *
+ * Switches from nids to uniqid.
+ */
+function serial_update_7130() {
+  // Get the new field schema.
+  module_load_include('inc', 'serial');
+  $table_schema = _serial_get_table_schema();
+  $uniqid_schema = $table_schema['fields']['uniqid'];
+
+  // Update the schema of old assistant tables.
+  $result = _serial_get_all_fields();
+  foreach ($result as $field) {
+    // Empty the table.
+    $table = _serial_get_table_name($field->bundle, $field->field_name);
+    db_delete($table)->execute();
+
+    // Drop nid field and key
+    db_drop_field($table, 'nid');
+    db_drop_unique_key($table, 'nid');
+
+    // Add uniqid field and key
+    db_add_field($table, 'uniqid', $uniqid_schema);
+    db_add_unique_key($table, 'uniqid', array('uniqid'));
+  }
+}
\ No newline at end of file
diff --git a/serial.module b/serial.module
index 6331866..d09eb47 100644
--- a/serial.module
+++ b/serial.module
@@ -10,7 +10,7 @@
 //==================//
 
 /**
- * Implementation of hook_field_info().
+ * Implements hook_field_info().
  */
 function serial_field_info() {
   return array(
@@ -24,7 +24,7 @@ function serial_field_info() {
 }
 
 /**
- * Implementation of hook_field_create_instance().
+ * Implements hook_field_create_instance().
  */
 function serial_field_create_instance($instance) {
   $field = field_read_field($instance['field_name']);
@@ -45,7 +45,7 @@ function serial_field_create_instance($instance) {
 }
 
 /**
- * Implementation of hook_field_delete_instance().
+ * Implements hook_field_delete_instance().
  */
 function serial_field_delete_instance($instance) {
   $field = field_read_field($instance['field_name']);
@@ -57,7 +57,7 @@ function serial_field_delete_instance($instance) {
 }
 
 /**
- * Implementation of hook_form_alter().
+ * Implements hook_form_alter().
  */
 function serial_form_alter(&$form, $form_state, $form_id) {
 
@@ -76,37 +76,50 @@ function serial_form_alter(&$form, $form_state, $form_id) {
 }
 
 /**
- * Implementation of hook_field_insert().
+ * Implements hook_field_presave().
  */
-function serial_field_insert($entity_type, $entity, $field, $instance, $langcode, &$items) {
-    module_load_include('inc', 'serial');
-    $sid = _serial_generate_value($entity->nid, $instance['bundle'], $field['field_name']);
+function serial_field_presave($entity_type, $entity, $field, $instance, $langcode, &$items) {
+  module_load_include('inc', 'serial');
+  if (empty($items)) {
+    $sid = _serial_generate_value($instance['bundle'], $field['field_name']);
     $items = array(array('value' => $sid));
-    $entity->$field['field_name'] = $items;
+  }
 }
 
+
 /**
- * Implementation of hook_field_is_empty().
+ * Implements hook_field_is_empty().
  */
 function serial_field_is_empty($item, $field) {
   return FALSE; // never should be treated as empty
 }
 
 /**
- * Implementation of hook_node_type_update()
+ * Implements hook_node_presave().
  */
-function serial_node_type_update($info) {
-    // Handle content type rename:
-    if (isset($info->old_type) && ($info->old_type != $info->type)) {
-      module_load_include('inc', 'serial');
-      _serial_rename_tables($info->old_type, $info->type);
+function serial_node_presave($node) {
+  if (module_exists('auto_nodetitle')) {
+    if (auto_nodetitle_get_setting($node->type)) {
+      auto_nodetitle_set_title($node);
     }
+  }
+}
+
+/**
+ * Implements hook_node_type_update().
+ */
+function serial_node_type_update($info) {
+  // Handle content type rename:
+  if (isset($info->old_type) && ($info->old_type != $info->type)) {
+    module_load_include('inc', 'serial');
+    _serial_rename_tables($info->old_type, $info->type);
+  }
 }
 
 // Tokens for fields are currently not supported - http://drupal.org/node/691078.
 
 ///**
-// * Implementation of hook_token_info().
+// * Implements hook_token_info().
 // */
 //function serial_token_info() {
 //  $type = array(
@@ -126,7 +139,7 @@ function serial_node_type_update($info) {
 //}
 //
 ///**
-// * Implementation of hook_tokens().
+// * Implements hook_tokens().
 // */
 //function serial_tokens($type, $tokens, $data, $options) {
 //  // TODO
@@ -137,7 +150,7 @@ function serial_node_type_update($info) {
 //=================//
 
 /**
- * Implementation of hook_field_formatter_info().
+ * Implements hook_field_formatter_info().
  */
 function serial_field_formatter_info() {
   return array(
@@ -165,12 +178,12 @@ function serial_field_formatter_view($entity_type, $entity, $field, $instance, $
   return $element;
 }
 
-/****************************************************************************
- ** Theme Functions *********************************************************
-/****************************************************************************/
+/**
+ * Theme Functions
+ */
 
 /**
- * Implementation of hook_theme().
+ * Implements hook_theme().
  */
 function serial_theme() {
 
@@ -196,7 +209,7 @@ function theme_serial_formatter_default($variables) {
 //==============//
 
 /**
- * Implementation of hook_field_widget_info().
+ * Implements hook_field_widget_info().
  */
 function serial_field_widget_info() {
   return array(
@@ -208,7 +221,7 @@ function serial_field_widget_info() {
 }
 
 /**
- * Implementation of hook_field_widget().
+ * Implements hook_field_widget().
  */
 function serial_field_widget(&$form, &$form_state, $field, $instance, $items, $delta = 0) {
   return array(
@@ -217,5 +230,4 @@ function serial_field_widget(&$form, &$form_state, $field, $instance, $items, $d
       '#default_value' => $items[$delta]['value'],
     )
   );
-}
-
+}
\ No newline at end of file