It must have something to do with how mu 3.1 redirects admin page requests because as soon as you refresh the page after the 404 you get when just using action=”../options.php” or a direct link – well the real options.php page comes up.
I am a programmer and am looking for a solution to this. It is not a hard-coded form action location. If anyone has any solutions let me know, I will post mine here when I find it.