Enable debug mode on the nagevlog agent, and verify that the test event you are creating is matching a filter you have defined and being sent on the NSCA.
Then check your nagios log to see if the passive check result is being received from NSCA, and if it is being accepted by Nagios.
Possible problems -
1) You do not have your filter defined correctly in NagEventLog
2) You do not have your hostname configured correctly in nagevlog
3) The matching filter does not have a correct service name defined in nagevlog
4) NSCA is ont passing the alerts on to nagios
5) Nagios is not configured to process the nagios.cmd file correctly
6) The received alerts have incorrect hostname/servicedesc and are being rejected by Nagios
7) You have the check frequency set far too low in nagevlog

the nagevlog service has not been started successfully