How long do traps/windows events show on the event manager console?
The time that an event shows on the event manager console is governed by the <auto-clear> option as described in the User Guide at http://help.kaseya.com/webhelp/EN/tv/9010000/index.asp#17207.htm
The trap rules file specify these values. The default rules file shipped with the product are to be found under <TRAVERSE_HOME>\etc\messages. Any customized rules files may be found at <TRAVERSE_HOME>\plugin\messages
You may determine the rule that was matched by generating the Message Event History as Reports --> Custom --> Message Event History. The Message Type column matches the description field in the rules files.