Function not listening to setInterval array

Hi all,

I have a random array of times in milliseconds, of which I want a function to be called on. Problem is, it seems to be ignoring the times in the array, and instead using the number of items in the array as a guage of how fast it should call the function. Any pointers?


 thingIntervals = new Array(200, 3000, 5000);
createThingSpeed = Math.ceil(Math.random()*thingIntervals.length*1000);
createThingID = setInterval(attachAnim, createThingSpeed);
thisThing = 0;
function attachAnim() {
     _root.attachMovie("item"+Math.ceil(Math.random()*7)+"path"+Math.ceil(Math.random()*4), newAnimation, thisThing++);