Zabbix 1.4.1: Expression [{12731}=0&{12730}=0] cannot be evaluated?

[welkin]

I have this trigger :

{Netscreen_1:icmpping.min(#4)}=0&{Core_Switch_3:ic mpping.min(#4)}=0

This should trigger when on both hosts the last 4 Pings fail. But actually this trigger is always on although the values for Netscreen_1:icmpping.min and Core_Switch_3:icmpping.min are "1" and not "0".
I get this error message in the logs

Expression [{12731}=0&{12730}=0] cannot be evaluated [Una
ble to get value for functionid [12731]]

any ideas ?

greetings
welkin

[StanZoid]

Try this:
({Netscreen_1:icmpping.min(#4)}=0)&({Core_Switch_3 :icmpping.min(#4)}=0)

StanZoid

[welkin]

thanks this worked.
i'm getting closer to setting up triggers the right way.

greetings
welkin