I can shed some more light on the the problems that have dogged me and many other ZA users recently.
of the PCs on our peer-to-peer network of XP machines fell sick after a reboot and ZAV spent 12 hours endlessly looping
and creating thousands of
files in \Windows\Internet Logs.

That machine was cured by the by-now standard procedure of Safe Mode deletion of all ZA's configuration files.
The cause of our problems appears to be that we renamed some of our work stations.
Windows XP attempts to open a connection to every device in a PC's Network Neighborhood, by a process that Microsoft does not seem to document very clearly.

If a device does not exist, because its name is wrong, XP will make repeated (I don't know how many) attempts to connect.
We got lots of messages to the effect that the network was not accessible because too many connections had been attempted to a particular PC, which was strange because XP Pro is supposed not to have a limit like XP Home.
Our network problems and our ZAV problems seem to have disappeared (fingers crossed!) after a root-and-branch clean-up of names across
our network.
Quite when a name gets entered into Network Neighborhood I don't know (and there seems to be some rising-from-the-dead like a virus infection) but you need to hunt down all users' folders called Nethood to delete bad names, and also all printers named in Control Panel.
You don't need to have multiple computers on-site to get this problem, because even a remote device somewhere on the Internet can be entered into Network Neighborhood.
One of the fundamental gripes against Windows has always been that it makes no distinction between local and remote networks.
As for where ZA comes into this story, I can only suggest that its gets as confused as me by all the early "Hello, are you there?" messages ping-ponging around when a PC starts up.

Operating System:Windows XP Pro
Software Version:7.0
Product Name:ZoneAlarm Antivirus