It is better to contact directly the ZA technical support at the link in my signature. Look for the live chat icon once you are at the main support site. Best to chat with them during the working days.
Before doing so, fully remove your current ZA on your system, let windows 8 re-activate the windows firewall or any other software (DO NOT disable them before installing ZA). Then download the latest build of ZA (yes, you don't get an automatic warning about new builds but only major releases). Looking for the latest version?
. Install ZA Extreme on default settings, replicate the issue and then contact official support.
Let us know how you solved your problem and who was the culprit. It may help other users here with similar problems.