Hiya
f-secure is an anti-virus program, whereas Zone Alarm is just a firewall. What was the problems that you had with those two?
However, did you fully remove f-secure? If you're not sure, take a look at this:
http://support.f-secure.com/enu/home/downloads/removeav.shtml
Do you have ZoneAlarm Pro 3 or 4?
can't link to this bit, but can copy/paste:
First, check in the upper right-hand corner of the ZoneAlarm Window. You should see an All Systems Active message in green letters (to the right of the lock). If the panel is displaying All systems Active and ZoneAlarm is still not functioning properly, it is possible that some files have become corrupt. To repair this problem, please follow the steps in this article.
http://nh2.nohold.net/noHoldCust25/Prod_1/Articles55646/corruptlogs.html
Regards
eddie