diff -r 777f32ac6b7c -r 1e956881d362 plugins/admin/PageManager.php
--- a/plugins/admin/PageManager.php	Sat Sep 26 15:21:51 2009 -0400
+++ b/plugins/admin/PageManager.php	Sat Sep 26 15:26:14 2009 -0400
@@ -150,7 +150,7 @@
             // Field: page URL string
             $page_urlname = $_POST['page_urlname'];
             $page_urlname = trim($_POST['page_urlname']);
-            if ( empty($page_urlname) && get_main_page() !== '' )
+            if ( empty($page_urlname) && !have_blank_urlname_page() )
             {
               $errors[] = $lang->get('acppm_err_invalid_url_string');
             }