Vanilla 2

hi, I have a problem with pretty Photo gallery and I need help. This is my situation:
If I select a picture on web page ("http://www.no-margin-for-errors.com/projects/prettyphoto-jquery-lightbox-clone#prettyPhoto[pp_gal]/0/") I view the photo and I can click in the right side of the popup for view the other photos (1,2,3 ecc). After this work I click esc for close the popup and I view the page with the initial thumbnails. Now if i click on the left arrow on the browser i don't view the page before the actual page: I stay in the actual page and in the address bar I see all the link about the image that I had seen in the popup (3,2,1).
For me this is an error, can I resolve it?
thanks
nervo.doc