My webpage has float: right; CSS and so the images put there seems like the first is the last one on a line. If you can't understand you can check here http://www.inkt.fdchost.com/claudia. Just click an image and you will understand. The webpage is in spanish language but it doesn't matters.
I think it will be somewhat good if I can order the Shadowbox images myself and non automatic like.
a href="a.jpg" rel"shadowbox[something].1"
a href="b.jpg" rel"shadowbox[something].1"