Vlk, the problem occured when using Kerio and the Application Behavior Blocking monitor (one application started by another).
It's not only with the second option (HIPS) that is only available in the paid version of Kerio.
On the freeware version, even without HIPS, avast antikill feature 'conflicts' with the Application Behavior Blocking.
I don't know if this will be a problem or not... With Comodo firewall, which does not have this feature, no problem.
Will this feature conflict with System Safe Monitor as stated above?