Running ZA Free 7.0.483.000 on XP SP3.

I've tried twice now to uninstall ZA in favor of different firewalls, and both times it corrupts what I believe is the explorer shell. Whenever I click on the start menu links (e.g., network connections, printers and faxes, my documents), I get an error message (can't find the associated file) followed by a crash of Dr Watson, followed by a frozen computer.

The only way I've been able to fix the problem is to uninstall the new firewall (tried both Outpost and PC Tools) and reinstall ZA. So I'm pretty certain something's getting corrupted in the ZA uninstall process.

Any ideas? Thanks.