Buttons within a movie clip

I’m creating a special flash intro which contains a world map. The map contains roll-overs for all the continents (every continent is a movie clip). When the correct continent is clicked, a list of available countries will appear. So far so good.
The country names that appaer in the list are actually buttons with a RollOver-state and a getURL. When the movie is loaded everything, except for the buttons, works fine. The lists do appaer when a continent is clicked, but nothing happens when a country is clicked/rolled over.
Can someone help me figure out what is going wrong in my movie?

As I’m not a very experienced flash user I posted the .fla and .swf for your viewing on this temp webspace:

http://www.dancohr.com/worldmap/worldmap.fla
http://www.dancohr.com/worldmap/worldmap.swf

Many thanks in advance,

Torben Sonnemans