I'll now be watching for a few days, to see whether the HP Game Center software was what had been causing ZAP 8 to silently exit.
That software is included by HP with XP Media Center 2005.
Haven't heard the official position as to whether MCE is supported for ZAP. Other than this silent exit issue, I've successfully used ZAP for nearly 2 years under MCE 2005.
Operating System:Windows XP Pro
Product Name:ZoneAlarm Pro