Microsoft is warning Vista users about the upcoming Vista update - Service Pack 1, which "may be broken by the update. Most of the software hit by the upgrade are security programs that prevent Windows users falling prey to viruses, trojans and booby-trapped webpages.". The current list includes ZoneAlarm as one of the programs that may not work.
Full story on the Beeb website -
http://news.bbc.co.uk/1/hi/technology/7205059.stm