Error on logout

I am having a very strange behavior here...whenever I try to logout from our admin section, I get routed to 404 error page!

So can someone please help me and tell me why this might be happening?

Last thing I did before this problem started was that I added a rule in .htaccess so that if someone write /login/ instead of wp-login.php he/she will get routed to the login page....so it is not even related to the logout page!

Any advice will be highly appreciated