Bug on refresh post.php

Hi all,

I’m encountering a weird problem on saving posts. When someone refreshes the post.php page it automatically assigns the latest two categories to the post (it only displays the latest categories as checked even if they’re not assigned to the post).

I know the solution may be “do not refresh post.php!” but I haven’t found any solution to the problem and maybe this could be helpful to someone else encountering the same problem.