Still same problem.
Have parents-childs. If whole segment is going down, nagios send about parent notification, as it have to do. But after that nagios shutting down. Logs shows just :
1235826931] Caught SIGSEGV, shutting down...
 Nagios 3.0a4 starting... (PID=1022)
Edit. Nagios shutting down, when segment is online again and it should send the notification out.