This works for me running WordPress 4.1, PHP 5.4, and only Magic Fields 2 and my toolkit as plugins and using Firefox, Chrome and IE as browsers so there must be something different in our environments.
If you are NOT using Firefox, Chrome or IE as your browser can you try either Chrome or Firefox or IE?
As this functionality is from the Magic Fields 2 plugin itself can you disable my toolkit and see if the problem persists. If you have used any of my toolkit’s additional field types (alt_*) you will get error messages if you use any post type with these fields (since these new field types will not exists) so you may need to create a new post type to test.
As I do not now know how to duplicate the problem in my environment I really need to understand more about your environment. What browser are you using? Specifically, what additional plugins are you using? What version of WordPress and PHP are you using.?
If you know how to access the PHP error log and your browsers error log I would appreciate knowing the error messages.
mc