It's probably a bot attack - just hitting all IP's within a certain range on port 1434 (Slammer worm). The log is saying that
it's blocked basically so there is nothing you can do. Check again to make sure you are stealth from ZA free and that's about it. When using a 3rd party firewall like ZA you should disable the IDS (network protection) of KAV....correct way to disable ids...
1) Click 'Settings'tab
2) Click 'Configure Real-Time Protection'
3) Click 'Network' tab
4) Un Check 'Enable real-time protection against network attacks'