Index: fb_settings.inc
===================================================================
--- fb_settings.inc	(revision 2941)
+++ fb_settings.inc	(working copy)
@@ -226,8 +226,9 @@
 
 if (fb_settings(FB_SETTINGS_TYPE) != FB_SETTINGS_TYPE_CONNECT) {
   // Cookie domain unique to app and page type.
+  $unique_id = fb_settings(FB_SETTINGS_APIKEY) ? fb_settings(FB_SETTINGS_APIKEY) : fb_settings(FB_SETTINGS_ID);
   $cookie_domain = isset($cookie_domain) ? $cookie_domain : '' .
-    fb_settings(FB_SETTINGS_TYPE) . fb_settings(FB_SETTINGS_APIKEY) . fb_settings(FB_SETTINGS_ID);
+    fb_settings(FB_SETTINGS_TYPE) . $unique_id;
   fb_settings(FB_SETTINGS_COOKIE_DOMAIN, $cookie_domain); // for debugging.
 }
 if (fb_settings(FB_SETTINGS_FBU)) {