I may be on vista but I've never had this issue with any game before, and I have a fair amount of them. The only games that I've had this issue with with Steam are game shortcuts that I add myself, Steam gets "unhooked" from the short cut so it no longer will say I am in game, that is the only time.

I found a thread on Steams forums about this, and follow the suggestions there (which simply stated to go into the Steam install path and make all the exe's run as admin) and it did not help.

I could care less about the fullscreen issue (which I've also never had before with any other game) as I plan on running it in borderless window, but the steam tracking really irks me alot that I can't find a solution to it, and such a small sample of people even seem to have the issue in the first place.