The navigation bar works fine for IE and FF, but does not always load a new album when using Chrome. For example, if you click on Portfolio and select Fine Art/Natura and then try to go through the navigation bar to the album "Waterscape", the "Natura" album reloads again.
What version of Chrome are you using? Chrome 16 was extremely buggy for many users due to conflicts with internal plug-ins such as flash and the pdf reader, causing many problems similar to this. Version 17 was released a few days ago and seems to have resolved the problems.