That would be a problem with Steam Cloud, not with the game itself... turn that off (yes, you can do that) and it should stop acting up.
Appreciate the response. Managed it out all the same. In my view though, it's a problem that occurs between the two entities [FONV and Steam Cloud]. Most likely some interaction that doesn't behave as anticipated with Steam Cloud, given that Steam Cloud doesn't have a problem with the other games it works with. It is still something that needed to be tested, just the same as if the problem were caused by a virtual store issue with Vista/Win7 if the game required/supported Vista/Win7.
To be fair, from what I understand, the option is no longer on by default for FONV, which is also a good thing.