Microsoft's inability to understand that not all software needs to be cloud based, or floated across your PC to a tablet to a Windows phone to an XboxOne is a common theme throughout Win8. The correct handling of local registry keys is one of the amusing epic failures of Win8.
The way round it is to disconnect your Windows8 Microsoft cloud based account and switch the machine to use a good old PC local account. (Desktop Configuration Tool Icon > Change PC Configuration > Users > Your account) where the registry keys work properly and you can configure your PAC IP addresses using PAC Terminal and still expect to find them in the same place when you next log on.
Microsoft continue to "upgrade" Windows8 on a daily basis. Quite often, (usually on Tuesdays and Thursdays) they even manage to mess this functionality up and all Opto22 controllers appear reconfigured as 255.255.255.255 in PACTerminal. If this happens, either wind back the operating system to the previous day or just wait until the next day when Microsoft suddenly realise that they have messed up again and schedule a new "upgrade". Better still, don't let Microsoft near your PC when its working.
Looks like all available resources in Microsoft are being employed on reimplementing the "Start" button in 8.1.