Missing firewall log

Friends

I have set Comodo to enable all three logs, but the firewall log file has been empty ever since I started using Comodo (several months ago(. The two other logs catch several things, but the Firewall has never caught enything, if I am supposed to believe the log. But I am sure there has been firewall events but the log just has not recorded them.

How can I be sure that the firewall is really working? How can I get the firewall log file to work?

I am using the latest free version of Comodo
Thinkpad T61P
Vista Ultimate

I do have a router with a firewall but other software firewalls that I used has cought stuff so the hardware firewall is not foolproof. So I believe that there is a problem with the log file, and that the issue is not that the hardware fw really catches everyhing so that the sofware one does have nothing to do.

Thanks for suggestions on this
Calle