Another question. I havge version 2.22 and I'm calling SubscribeToPropertyChange("System Time", "Time Without Seconds"). Also I have PropertyChangeNotification defined in my class but it never seems to get called.
It sounds like, perhaps, that HBPropertyChangeNotification isn't exported in your plugin (forgot to mention that to you earlier). Check out the code at the very bottom of DeviceTemplate.cpp in the SDK sample and see an example of how it is being exported and how it calls the Device object. You can pretty much just copy/paste that code.