Proxomitron could be the ‘bad guy’ here.
Is this program redirecting the traffic to a local proxy (127.0.0.1 for instance)?
The problem is, why Kerio is asking for this access if no other firewall do?

Whatever circunstances is the problem here… your configuration could be different that the default ones. I’ve already said that I use avast fore almost 2 years and only avast.setup for updates and ashMaiSv.exe the avast email scanner have asked for Internet connection.