BOAC, honestly, remove it. I understand your concerns, but it really will benefit you in the long run to replace it with the Windows firewall.
I have several hundred customers currently under my support, and whilst I don't participate in computer holy-wars about what is or isn't best I have looked at ZoneAlarm several times over the past decade and concluded it wasn't supportable. Also I was looking for a firewall product to deploy to 100,000 PCs in 2000 and still couldn't recommend ZoneAlarm despite working with the manufacturers at the time. It's just not architected in a way that'll ensure supportability long-term.