Okay as I was waiting for a reply I decided to view alot of Photopost sites in safari and see no issues. Here is my site.
http://www.reeftalk.com/gallery/index.php
I can only conclude somewhere in your html code you have a missing html tag which is throwing things off. This would appear to be your issue your header and such as you have 136 validation errors on your page for the html.
http://validator.w3.org/check?uri=ht...Inline&group=0