Index: units/users/users_event_handler.php
===================================================================
--- units/users/users_event_handler.php	(revision 14094)
+++ units/users/users_event_handler.php	(working copy)
@@ -515,8 +515,10 @@
 			if (!$this->isSubscriberOnly($event, true)) {
 				$cs_helper->CheckStateField($event, 'State', 'Country');
 			}
-
-			$this->_makePasswordRequired($event);
+			else {
+				// no need to make password required when guest user tries to subscribe to mailing
+				$this->_makePasswordRequired($event);
+			}
 			$cs_helper->PopulateStates($event, 'State', 'Country');
 
 			$object =& $event->getObject();