I don't recall ever seeing that issue before. It's a strange bug indeed. And I'm using the word bug here, since I'm 99% confident that it isn't "normal" behavior. Is that the Black Edition on Steam? That's the version I have. I haven't played it in a very long time (more than a year by now I think), but as far as I can recall I've never had my score 'wiping' or reverting to zero after briefly showing up. The only thing I can recommend for now is to do a files Integrity check from the properties (if that's the Steam version that is). And if that doesn't work, uninstall and reinstall (maybe it didn't install something important during the first-launch installation process... although I don't even remember if it installs anything during the first launch, such as Visual C++ Redist packages for example).