I have read messages on this problem (which is also driving me up the wall) and have done everything recommended by Slyfox, including deleting backup.rdb and iam.rdb files in the internet logs folder, then done a reboot in normal mode.
Nothing has worked.
This has only happened since the update to 6.1.744.1.
Is there anything else I can try?

Operating System:Windows XP Home Edition
Product Name:ZoneAlarm (Free)
Software Version:6.1