Quick Navigation Question

hopefully an easy one…
first click this www.anobleworld.com/flash/InvestmentTools/SelectionTool_new.swf

when you click on the navigation tabs once… it no longer works…i.e. as you can see you can click all the way down, but you can’t do the opposite.

snapshot of my timeline…

each frame has stop(); (menu_co… layer) if that helps… what am I doing wrong?

I really want to learn… so thanks in advance for your help.