Hi!

Zabbix Server 2.2.6

I have some item with interval 900s with latest data:
07.???.2015 22:46:14 91
07.???.2015 22:31:14 92
07.???.2015 22:16:15 91
07.???.2015 22:01:14 93
07.???.2015 21:46:14 92
07.???.2015 21:31:14 91
07.???.2015 21:16:14 92
07.???.2015 21:01:14 91
07.???.2015 20:46:14 93
07.???.2015 20:31:14 92
07.???.2015 20:16:14 91
07.???.2015 20:01:14 92
07.???.2015 19:46:14 91
07.???.2015 19:31:14 93
07.???.2015 19:16:14 92
07.???.2015 19:01:14 91
07.???.2015 18:46:14 88
07.???.2015 18:31:14 85
07.???.2015 18:16:14 89
07.???.2015 18:06:14 87

And I have trigger with hysteresis:
({TRIGGER.VALUE}=0&{some_host:some_item.count(#5,90,"ge")}>4)|({TRIGGER.VALUE}=1&{some_host:some_item.count(#8,90,"lt")}>7)

An item is checked every 15 minutes. I have a trigger with the following condition:
the trigger should change its status from "Ok" to "Problem" when last 5 values of the item are equal or bigger 90 (each value of last 5).
the trigger should change its status from "Problem" to "Ok" when last 8 values of the item are less than 90 (each value of last 8).

But trigger changes value on every check from "OK" to "Problem" and back from "Problem" to "OK"

Is it bug?