This on automatic updates:
http://blog.washingtonpost.com/securityfix/2006/10/zonealarms_new_autoupdater_pro.html
Should be working on the free version:
The guy I met forwarded my query to Laura Yecies, vice president and general manager of CheckPoint's consumer and small business division. Turns out that sometime in June an update the company shipped to the (free and pay) 6.5.x versions of ZoneAlarm allows the program to silently download and install fixes on its own. Yecies said the company switched on the auto-update for two reasons.
Here are the latest changes:
http://download.zonelabs.com/bin/free/information/zap/releaseHistory.html#7.0.337.000
You can always download the latest version and slect ‘upgrade’ when installing.