I agree, mistakes in titles are just a big no no. I can see missing it before you hit the publish button, but we can edit our titles at any time, so are people just not reading their own stuff? I hate to say it, but some writers are just lazy; that;s the only way I can explain it. I have 200 published titles, and I defy anyone to find a typo in one of them. I guess there's something to be said for an obssessive compulsive personality :-)