Some module is adding info below 'Nice Menus' I believe some module is somehow hooking into nice menus and adding a div of content below the menu. However I can't for the life of me find out which one.

Here's what I know:

There is a content type called 'nice_menu_addition'. When creating an item of that content type you chose which menu item you would like it placed beneath, and it shows up there. However, I can't find ANY modules anywhere, or any theme info that shows where this is being done. Any suggestions as to where to look?
suggestion from average drupal guy.... try using the module_implements() with watchdog method to check the available hooks from nice menu or menu docs that can cause the change and track the module...hope it helps you in some way