Index: includes/session.php
===================================================================
--- includes/session.php	(Revision 9356)
+++ includes/session.php	(Arbeitskopie)
@@ -480,7 +480,7 @@
 
 				foreach (explode(',', $row['bot_ip']) as $bot_ip)
 				{
-					if (strpos($this->ip, $bot_ip) === 0)
+					if ($bot_ip && strpos($this->ip, $bot_ip) === 0)
 					{
 						$bot = (int) $row['user_id'];
 						break;