Problems for author posting to a category

I’ve got one of my contributors/authors posting to her category but when she does it doesn’t go to her category, it goes to Uncategorized which is what first appear in the category sidebar on the right of the write post page.

So she adds her category, checks it on, unchecks uncategorized, then publishes it. But it is going still to the uncategorized category even though it’s unchecked! Why is this happening? I do have role manager on but I have Manage Category checked on. Should I also have Post to any Category also checked on?