ie7上灯箱2的javascript问题

I am having a problem with lightbox2 on IE7. I've modified lightbox, moved the navigation around a bit - everything works fine on Firefox but in IE7 there is a problem: the first time I click on a thumbnail only a part of the background dims and the large image doesn't show. If i try again it works, the problem only occurs after a full pageload.I am having a problem with lightbox2 on IE7. I'