proxy not marking agent as unavailable

When we shutdown a host that is monitored by a proxy the proxy keeps on polling the agent and never marks it as unavailable.

This causes the poller node on the proxy to increase significantly. If more than one host is off sometimes the proxy's pollers get overloaded and we lose data.

Attached a debug 4 proxy log. The http://zabbix/chart2.php?graphid=23810&period=3600&stime=20160326142616&updateProfile=1&profileIdx=web.screens&profileIdx2=23810&sid=a5ac39ae33787e50&width=1776&curtime=1395905176900host that was offline is ldb019