Random number variable followed when thickbox "pop-up"

Hey guys, I met another problem, the enlarge function of product picture does not work now, when I click the picture, the ajax "pop-up" window show the index page not the picture in cache directory.

Watch the requests of the page sent, found there is a variable named "random" follow the picture name:

aaa-500x500.jpg&random=1251943903622

I think this value cause the picture address unavailable, so thickbox redirected to index page. Does anyone have any idea about this random variable? Where did it come from? And how to remove it?

Thanks!!!

Problem Fixed!

In thinkbox.js line 234:

$("#TB_ajaxContent").load(url += "&random=" + (new Date().getTime()),function(){//to do a post change this load method

I don't know why it use "&", it does not work as a legal url when following a file, such as "abc.jpg&random=xxx", just change it into "?", it's all set!