Your link isn't working anymore for me to look at the updated page. Your version of PowerGallery is current, so that is good.
It still sounds to me like there is other code of the page that is interfering with the PowerGallery code that is trying to run. I would start with a blank page that only has the skeleton structure and that has the PowerGallery code on it. See if that loads ok then add in your other code piece by piece to see what is causing the issue.
Looking at some of the other pages, there appear to be 404 errors for some of the include files and other errors. Its possible things like that are affecting the PowerGallery code too.