using the 1.2.0 version.
i had a power failure that effected some servers but not the netxms server and my console.
i have received an alarm on a domain controller for being down but pinging it was successful.
i have waited about a minute or two just to be sure that it gets status polled and things were still the same.
now i can not remember if i polled the node or tried to delete the alarm first but when trying to delete the alarm it gave me an error.
basically, the alarm browser refresh was maybe sluggish or slow responsive or whatever.

Lindeamon