Problem with navigation menu

I just added a link to my navigation menu and rearranged the order of a couple of links. Now on my website when I clink on a link on my navigational menu it goes to the right page but the wrong page name is highlighted on the navigational menu. How can I fix this?
The website address is www.prestigeknowledge.com. When I click on Photo Gallery from the navigational menu it takes me to the 'Photo Gallery' page but 'Video Series' is highlighted on the navigational menu instead of 'Photo Gallery'. Also, when I click on 'Reviews' on the navigational menu it goes to the correct page but 'Photo Gallery' is highlighted on the navigational menu instead of 'Reviews'. Everything else on the navigational menu is working properly. It's just those two. I have tried deleting those links and then adding them back again but the same thing keeps happening. Can anyone help?