Win98? Yep, that would require an older version, I see what you mean, but Comodo and PCTools firewalls require Win2000 according to the specs, don't they?
I've heard talk that the latest version of ZA is buggy, and I think it's mauserme that always recommends older versions even on XP, but I've found that the latest version doesn't have the bugs that ZA used to have: not keeping rules after a reboot and removal/ reinstall problems.
Sorry about the confusion.