This issue doesn't appear anymore, since the problem I described in my thread "RegEx VHost name and the default VHost" (http://forum.nginx.org/read.php?2,235490) is resolved (solution: http://forum.nginx.org/read.php?2,235490,235500#msg-235500). Posted at Nginx Forum: http://forum.nginx.org/read.php?2,235411,235506#msg-235506