jQuery setTimeout issue

I have a simple function that animates a bunch of images by crossfading them. A simple banner rotation. I set up the function so that calling animateSlideshow("play") it should set the timeout and start animating and by calling animateSlideshow("stop") it should stop.

When I call stop, however, the animation happens one more time. What is the cause for this one extra animation and how can I deal with it?

function animateSlideshow(action){



    if(action === "play"){

        $(activeSlide).data('animateSlideshow', 

            setTimeout(function(){



                if( $(actvImg).index() === total - 1 ){

                    $(actvImg).fadeOut(animationSpeed).removeClass("actvImg").siblings().eq(0).fadeIn(animationSpeed).addClass("actvImg");

                }else{

                    $(actvImg).fadeOut(animationSpeed).removeClass("actvImg").next().fadeIn(animationSpeed).addClass("actvImg");

                }



                actvImg = $(".rightSlides li.active .rightSlide > li.actvImg");

                actvImgIndx = $(actvImg).index();

                updateBreadcrumbs();

                animateSlideshow("play")



            }, animationTimeout)

        );

    }else{

        clearTimeout($(activeSlide).data('animateSlideshow'));

    };



};