Index: includes/admin.settings.inc
=========================================================
--- includes/admin.settings.inc	(revision 1.2.2.5)
+++ includes/admin.settings.inc	Sat Oct 16 13:18:30 CEST 2010
@@ -35,6 +35,13 @@
     '#collapsible' => TRUE,
     '#collapsed' => TRUE,
   );
+
+  $form['adv_settings']['signup_addusers2closed'] = array(
+    '#title' => t('Allow administrators to add users after signup have closed.'),
+    '#type' => 'checkbox',
+    '#default_value' => variable_get('signup_addusers2closed', false),
+  );
+
   $form['adv_settings']['signup_date_format'] = array(
     '#title' => t('Format string for displaying signup-related dates'),
     '#type' => 'select',
Index: includes/signup_form.inc
=========================================================
--- includes/signup_form.inc	(revision 1.1.2.1)
+++ includes/signup_form.inc	Sat Oct 16 13:18:30 CEST 2010
@@ -194,7 +194,7 @@
 
 function signup_node_admin_add_user_page($node) {
   $output = '';
-  if ($node->signup_status) {
+  if ($node->signup_status || variable_get('signup_addusers2closed', false)) {
     $output = drupal_get_form('signup_form', $node, 'admin', FALSE);
   }
   return $output;
Index: signup.module
=========================================================
--- signup.module	(revision 1.242)
+++ signup.module	Sat Oct 16 13:18:30 CEST 2010
@@ -509,7 +509,7 @@
       return $admin_all || $admin_own;
 
     case 'add':
-      return ($node->signup_status && _signup_menu_access($node, 'admin'));
+      return (($node->signup_status || variable_get('signup_addusers2closed', false)) && _signup_menu_access($node, 'admin'));
 
     case 'broadcast':
       $email_all = user_access('email all signed up users');
@@ -1223,7 +1223,7 @@
   // If we made it this far, we're going to need the full user object.
   $account = user_load(array('uid' => $signup_form['uid']));
 
-  if ($node->signup_status) {
+  if ($node->signup_status || variable_get('signup_addusers2closed', false)) {
     // Grab the current time once, since we need it in a few places.
     $current_time = time();