strange, zabbix sents fake alarms

[robertchen]

I setup brocade switch temperate trigger like this:

{Brocade_FC_Switch:swSensorTempValue[{#SNMPVALUE}].min(3600)}>40

I got many trigger alerts emails:

Trigger: Temperature SLOT #0: TEMP #2 is above 40°C (31 °C)

it is 31, why 31 is above 40?

thanks,
Robert