I installed zapsetup 70_483_000 on an XP Pro machine using the upgrade - not the clean install, and it went very smooth.
After the install, I clicked on the Microsoft medallion to install the KB951748 security patch - shut down as instructed after the install, and was able to access the internet with no problems following the restart.
I don't know what those of you that say this doesn't work did, but it does work and fixes the problem.
Operating System:Windows XP Pro
Product Name:ZoneAlarm Pro