If I understand correctly, when you open MintMenu, all you see is the normal left-hand part of it, i.e., Places and System. If that is the case, do you see a tiny icon with a triangle+scissors? If you click on that it should being back the application part of the menu. If not you may have hidden this part too, try clicking on either the bold Places or System to see what I mean.
If thats not what you meant, then I don't know what you mean.