I replayed Half-Life 2: Episode 2 earlier this year, getting all the remaining achievements that I didn't get in my first playthrough.
So to my surprise, when I was just looking through my Steam list I noticed that I only had 95% (21/22) of the achievements - it tells me I'm missing Neighbourhood Watch. I know that I definitely got all of the achievements in the game, including Neighbourhood Watch.
So I decided to fire up Episode 2 and double check. Sure enough, in game it tells me I have 100% of the achievements, but on Steam it tells me I have 95%:
Not sure what I should do about this.
Has anyone had this sort of thing happen before? Is there anything that can be done about it? Could this possibly have something to do with running the Steam Beta? =/