Problems with Light box/Flickr

I have uploaded both the light box 2.0 versions as well as the flickr program to put in a “picture show” on my site. I have the pictures, the flickr account and everything works… up until I click on the picture on my page. The screen dims like it should, the “black box” appears where the picture is going to go… but nothing loads. What am I doing wrong? I can’t figure it out. Can someone help? Thanks.