Once the buttons are inserted into the movie clip symbol, the actions will no longer work for the main timeline. You need to add _root. to tell it to affect the root timeline of the movie
Code:
_root.gotoAndPlay(YOUR SCENE/FRAME HERE);
If you still have trouble, post your .fla file up here.
Sorry about that, it's a long time since I've used scenes....
It doesn't like targeting a scene from within another movie clip, so what you need to do is put a frame label on the frame in the scene you are trying to get to, and then target that with your link.
For example, if you want to get to the first frame of the second scene and you label that frame "scn2fr1", you would use the following code on your button within the movie clip:
Code:
on (press) {
_root.gotoAndPlay("scn2fr1");
}
Hope this is clear enough for you. I've attached a sample file just incase it helps.