Picture Slider w/ Movieclips

programming flash
1

Okay, So I am making a picture slider with movieclips being called from the library. There are 20 movieclips being played in a specific order. I can play the last 10 with no problems, the middle 5 is hit or miss, and the first 5 frames are usually skipped. Why is that? Here is the button code. I have already made sure that everything is labeled properly so idk.

nextBtn.onRelease = function()
{
_root.attachMovie(‘slideAA’, ‘slideAA_b’, getNextHighestDepth);
this.removeMovieClip(‘slideAA_b’);
nextFrame();
}

nextBtn.onRelease = function()
{
_root.attachMovie(‘slideIX’, ‘slideix_empty’, getNextHighestDepth);
this.removeMovieClip(‘slideix_empty’);
gotoAndPlay(“startFrame”);
}