Without seeing the timeline I can only hazard a guess.  If you have the same buttons along the full length of the timeline, then what is probably happening is you are assging all those listeners to them, and they all remain in effect, so by the end, clicking them triggers each of the listeners, where the last always wins.

Try using just one listener and function for each button assigned in frame one.  Use variables for the frame designations in the gotoAndPlay() calls.  Then you just need to change the values of the variables at different stages of the timeline.

The code for the buttons would not change very much and would only be in frame 1.  You would only be changing the functions to use variables for the gotoAndPlay() class

var fwdFrame:uint = ???; // use  whatever the value would be for the goto in frame 1 normally

var backFrame = 1;

fwd_btn.addEventListener(MouseEvent.CLICK, fl_goForward);

function  fl_goForward(event:MouseEvent):void {

     gotoAndPlay(fwdFrame);

}

back_btn.addEventListener(MouseEvent.CLICK, fl_goBack);

function fl_goBack(event:MouseEvent):void {

     gotoAndPlay(backFrame);

}

Make sure that layer extends the full tlength of the timeline so that the variables and functions are available all along it.

Then you just need to change the values of fedFrame and backFrame at each new stopping point on the timeline.

Don't redeclare the variables, just reassign them....

fwdFrame = "retailer_1";

backFrame = 1;

If you are going to use frame labels, then declare the variables as strings,  If you are going to use frame numbers, declare the variables as uint or int.  Stick with one type for all of them

Frame labels (which are strings) is a better choice, especially if you anticipate changing the timeline.  So you would just need to keep them all as String objects when you declare and assign them...

// frame 1

var fwdFrame:String = "retailer_1";

var backFrame:String = "someOtherLabel";

// other frames

fwdFrame = "omeOtherLabel3";

backFrame = "someOtherLabel2";