Horizontal scrolling use MOUSE_MOVE event problem

Hi, I have a a thumbnail scroller that scrolls images horizontally and inverted when I move the mouse.

It works fine on its own, and is giving me the results I want, but whenever I put it in my project, it won’t scroll properly.

Like, the scrolling is the same, but it doesnt just scroll the thumbnails anymore, it scrolls everything. The background image, page title, etc.

I’m sure I did something wrong, because I think this his been implented before with no problems, any ideas?

P.S When I put the scroller on the main timeline, this problem doesn’t happen. It only occurs when I put it within a movieclip.