alerts on value not changing within description?

[zac]

Greetings,


I put a monitor on our UPS system to monitor spikes in usage. the problem is the alerts happen where there is no change or are less then then the description

the trigger is {UPS:loada.change(0)}>20

the raw snmp values look like
SNMPv2-SMI::mib-2.33.1.4.4.1.5.1 = INTEGER: 59
SNMPv2-SMI::mib-2.33.1.4.4.1.5.1 = INTEGER: 61


and the action is an email alert with the subject of

{TRIGGER.NAME}: {STATUS} valuenow = {UPS:loada.last(0)} valuebefore ={UPS:loada.last(1)}

here's an example email

load spike on A Leg: ON valuenow = 60 valuebefore =60

the values returned from the snmp monitor are 2 digits stored as int64 with units=%

can anyone think of why I'd get this trigger firing when there isn't a jump of 20 in the value?


thanks

zabbix 1.4.2