AS3 Playback control of nested movieclips

Hey all,

I'm trying to figure out how to control a movieclip symbol from the timeline.

I've created a Main Timeline with one symbol per frame, a labels layer and an action layer.

Each frame has its own label, and each action keyframe has a listener attached to the current symbol like so:

symb = title_mc;

symb.cacheAsBitmap = true;

symb.mask = f_mask;

symb.focusRect = false;

stage.focus = symb;

symb.addEventListener(KeyboardEvent.KEY_DOWN, mc_pager);

I need the following structure:

1. From Main timeline Frame
2. Identify symbol instance (labeled as <name>_mc)
3. Inside symbol timeline, play from first frame (labeled '0') until next labeled frame ('1' and so on)
4. stop and wait for next pg_down to start playing from next labeled frame to the following (i.e. '1'-'2'), or pg_up to start playing from the previous labeled frame (i.e. '0' - '1')
5. on last frame (labeled 'final') exit symbol focus and return keyboard control to main timeline to allow pg_down and pg_up to move to the next / previous frame. on pg_up on symbol.currentFrame == 0, do same.

This is the code I'm currently stuck with:

import flash.events.Event;

import flash.display.MovieClip;

import flash.events.KeyboardEvent;

stage.displayState = StageDisplayState.FULL_SCREEN_INTERACTIVE;

stop();

f_mask.cacheAsBitmap = true;

var symb:MovieClip;

symb = MovieClip(root); //assign symbol I want to be controlled by pg_up/pg_down

symb.focusRect = false;

symb.addEventListener(KeyboardEvent.KEY_DOWN, mc_pager);  //add keyboard event listener

stage.focus = symb; //focus on current symbol

function mc_pager(e:KeyboardEvent):void{

    var myKey = e.keyCode;

    if (myKey == Keyboard.PAGE_DOWN){

        do{

            symb.play(); // it plays, then checks if the lbl is null or final, then quits

            trace("current: " + symb.currentFrameLabel);

        } while (symb.currentFrameLabel == null && symb.currentFrameLabel != 'final');

        symb.stop();

        symb.removeEventListener(KeyboardEvent.KEY_DOWN, mc_pager);

        stage.focus=MovieClip(root); //return focus to main timeline (in the next keyframes, the focus is on the nested _mc

    }

    if (myKey == Keyboard.PAGE_UP){

        do{

            symb.prevFrame();

        } while (symb.currentFrameLabel == null && symb.currentFrameLabel != '0');

        symb.stop();

        symb.removeEventListener(KeyboardEvent.KEY_DOWN, mc_pager);

        stage.focus=MovieClip(root);

    }

}

So far, I've tried several different things (including multiple eventhandlers) to no avail. This is what looks best so far, being logically sound (I think). But it doesn't work. Please, I need a hand with this.