It sounds like you should switch off the warnings if they are on. Yes that isn't unusual there are many infected systems out their trying to find other systems to infect ('port scanning' random IP addresses) or turn into zombies to send out spam or infection.
I never even look for attack detection stats in my firewall, they are history and the firewall is doing its job and blocking them. Basically it is the firewall trying to make you feel warm, fuzzy and protected. You could take the shields up check at grc.com. This checks the stealth of your system if it can't be seen it is less vulnerable to attack. Your firewall should have logs and you should be able to check them, I don't know how comprehensive these are in ZA free.
My system is very well stealthed and I don't see that kind of activity, only 8 detections today, all 'port scans' all to port 445
http://www.grc.com/port_445.htm a common attack port, which should be looked after by your firewall.