;D
Red,
Firstly, Pavel is correct. There are now 4 servers. I overlooked www.iavs.cz.
Anyway, I believe that the auto-update cycles ever 4 hours.
Kerio is a good firewall, but Rule based which can cause problems if the permissions are not set exact.
Check your traffice log to ascertain if Kerio is blocking any traffic to the destination hosts (4 servers).
If so, set rules to allow ANY type traffic incoming and outgoing to those specific destinations.
Hope this helps.