@bohenden - that's totally bizarre.
I have successfully installed the SS hack without problems on my KPW several times now.
I would try one more thing. Try to install another hack and see if that works on your PW. I wonder as well if you have a geographically different PW? This would be determined by the first 4 digits of your PW serial number.
I am grasping at straws. I am not a dev, but I have successfully used the great products of the devs here.