InformixHQ - alerts are reported only once

Hello, I am trying to configure alerts - I create 2 - one for Informix server is offline and second one for InformixHQ Agent is offline. When I started both InformixHQ server and InformixHQ agent and put db server offline or shutdown agent, I was alerted by e-mail, but when restart db server or inforgmixhq agent and after some time shutdown again - this time I did not receive alert mail, even if I Acknowleget first incident. I tested this with both e-mail alerting and runscript alerting. Can someone help me with this issue? What exactly akcnowledging means? Thanks a lot ------------------------------ Milan ------------------------------