MC won't work in Timeline - works fine on it's own

Hi Everyone,

I have a simpel 5 page website which is controlled by my main timeline. The first movieclip which is an animation works fine. The second movieclip which is an interactive scrolling gallery does not work.
(All the movie clips are controlled by the menu link buttons, which indicate which frame to play upon release).

When I test the scene on the movieclip itself, independent of the main timeline it works fine, however once I drop the instance into my main timeline it no longer works.

Can anyone help please? Any help is much appreciated.
Thank you.