The order of category list in Add New Post

Hi.
If you have some parent-child categories, they are shown with indents in Add New Post. But when you choose a child category and publish the post, after reloading the Add New Post, the selected category comes up and there is no indention.
It causes to confusing, if you have so many parent-child categories.
Is there any hack or any plugin to solve this or to change the way are shown, for example converting the default style to drop-down?