Loading SWFs pauses code execution?

I’m having trouble with a movie I’m making. It’s a loader movie clip that loads 3 seperate SWFs. The problem I’m having is that if I do:

mainLoader.addListener(mainListener);
mainLoader.loadClip(mainPath, main_mc);
menuLoader.addListener(menuListener);
menuLoader.loadClip(menuPath, menu_mc);
reservationsLoader.addListener(reservationsListener);
reservationsLoader.loadClip(reservationPath, reservations_mc);

Then all 3 movies sorta half-load and stop tweening at random points depending on how fast each ones loads.

If I add listeners thusly:

mainLoader.addListener(mainListener);
mainLoader.loadClip(mainPath, main_mc);
reservationsLoader.onLoadComplete = function() {
menuLoader.addListener(menuListener);
menuLoader.loadClip(menuPath, menu_mc);
reservations_mc.test();
}
mainLoader.onLoadComplete = function() {
reservationsLoader.addListener(reservationsListener);
reservationsLoader.loadClip(reservationPath, reservations_mc);
}

It works better but the fade in is still interrupted in the reservations SWF.

Is there something flash does in relation to externally loaded SWFs that I don’t understand? It seems like loading an swf into a movieclip shouldn’t even affect anything else.