I have had on-going errors trying to update my AV complement. Same error "Unable to connect to update server".
Same issue since last year. ZoneLabs is hopeless. After more than a year of trying to fix this error, it seems to me that the simplest workaround is to allow FTP downloads to happen for its registered users. ZoneLabs simply don't and won't listen. As for the diehards out there, well, for those of us who are experiencing the failure and the exasperations, then, please accept the realities of this product flaw. There is no point in defending the indefencable. So, ZoneLabs should release the signatures to us, so that we can get on with securing our machines - rather than being subjected to the technocrat egos who are punishing us all. I'm not interested in arguing the point. The best thing to do is refuse to buy ZoneLabs products. What a hopeless experience. Other products are looking good - in fact, everything else is looking good, at this point.

Win XP - SP-2.
ZoneAlarm Security Suite version:9.1.008.000
TrueVector version:9.1.008.000
Driver version:9.1.008.000
Anti-virus engine version:8.0.2.42
Anti-virus signature DAT file version:993960192
AntiSpam version:6.0.0.2383