Actually, I did
Yes, it fails because not all ports are "stealth". Some are "closed". Non are open, which is the most important. Had tried Comodo a while back, found it too heavy and rather complex. BTW I was running Kerio, which is probably what I'll go back to if I decide to uninstall PC Tools, although Kerio is also heavy (but very easy - I was never very good with firewalls, a necessary evil for me
).