Functional buttons stop working after reopening parent mc?

hello people,

i’m a flash newb, wrestling with actionscript 3 and ran into a problem with a drop down menu.
the menu is composed of nested movie clips that open and close, and contain buttons that control a ui loader in scene 1. it seemed to be working all right until i realized that after opening and closing and reopening a submenu, the buttons that worked the first time stopped controlling the ui loader. since there aren’t any error messages i’m kind of at a loss as to what needs fixing. maybe a timeline issue?

thanks for any help, you have no idea. if you could keep your vocabulary to something an idiot child could understand, i would definitely appreciate it.