One feature of Sygate that is not published is the ability to stop all active responses from your computer......which effectively makes it "dead" to the scanning computer.
Open up the Sygate Security log, highlight the traffic line and right click. Choose Stop active responses.
The scans should stop for the session.
I have the same trouble with ATT.
Good luck
"Active Response Protection—Active response is a feature that automatically blocks all communication from a source host once an attack has been detected. For example, if the Personal Firewall detects a DoS attack originating from a certain IP address, the Personal Firewall will automatically block any and all traffic from that IP for the duration specified in the seconds field. The user can now stop a current active response session."
- From the Sygate help file
Setting "Stop Active Responses" makes it so sygate no longer blocks traffic from that ip
You are doing it backward