My setInterval is not working properly?

Hi guys,

I did this cheesy banner for my portfolio and i dont understand why the setInterval is not working correctly. The thing is when I let the banner roll its working perfectly but as soon as I start to click every number very quickly the timer get all screw up I dont understand why… ??

this is the code is use

stop();
ID = setInterval(jump,16000);
function jump(){
play();
};

links:

http://www.chungludesign.com/_fla/banner-vacation.swf

and FLA

File name: banner-vacation.fla File size: 1.31 MB

thx in advance
Keelz