[Observium] Alerting not working on short flap

Hey guys

I have a weird problem on alerting system. One of my ethernet interface of a device went down for 10 minutes. I can see the flap in observium eventlog :

2014-04-29 15:18:28eth port-1-1-1-1Interface changed: [ifOperStatus] down -> up2014-04-29 15:08:28eth port-1-1-1-1Interface changed: [ifOperStatus] up -> down I have a specific alerting probe on "ifOperStatus equals down" but it has not been triggered :

http://observium.sipartech.fr/alert_check/alert_test_id=1/ETH PORT-1-1-1-1 Checks OK14s2h 59m 42s*Never* It usually work, but not this time. Is there a log or something that could help me understand why it did not ring the bell ?

Greg