My buttons flash on and off when I watch the .swf file

Hey Everyone,

So I haven't used actionscript 3 in a very long time and am still trying to get my head around the basics. I only studied it for a short period of time before hand aswell so I'm still

quite new.

Anyway, I have 5 buttons, all with movie clips in the up, over and down states. When I watch the .swf the navigation works fine when I click them and the animation plays when I hover over but the buttons flash on and off for some strange reason. I checked all my stop actions they are correct. Please help, this is for an assignment and I'm running out of time!

My code:

stop();

import flash.events.MouseEvent;

////// Rationale Button

rationale_btn.addEventListener(MouseEvent.CLICK, clickRationale);

function clickRationale(event:MouseEvent):void

{

  gotoAndPlay("rationale");

}

////// Dimensions Button

dimensions_btn.addEventListener(MouseEvent.CLICK, clickDimensions);

function clickDimensions(event:MouseEvent):void

{

gotoAndPlay("dimensions");

}

/////// Assessment Button

assessment_btn.addEventListener(MouseEvent.CLICK, clickAssessment);

function clickAssessment(event:MouseEvent):void

{

  gotoAndPlay("assessment");

}

//// Course Outline Button

courseoutline_btn.addEventListener(MouseEvent.CLICK, clickCourse);

function clickCourse(event:MouseEvent):void

{

  gotoAndPlay("course outline");

}

/////// Student Work Button

studentwork_btn.addEventListener(MouseEvent.CLICK, clickStudent);

function clickStudent(event:MouseEvent):void

{

  gotoAndPlay("student work");

}