I'm not sure if this has been fixed or not (I'm not even sure if it's a bug), but before when I used 1.2.2, I had posts belonging to multiple categories, and when I deleted those categories, the number in General (category) would go up by however categories the post belonged to.
E.g. I have a single post in my blog and I have the categories General, Books, and Films. If that post belonged to both the Books and Films category there would be a "(1)" beside each of them. If I then deleted both categories, I would end up with "General (2)" even though there's only one post.