When I visit the murals page I see an error about failing to include the page that has the gallery on it. If I try to visit the page directly I get a 404 error:
It looks like the file has been deleted or moved on the server. It seems that I cant browse to any files within the galleries area. What is the name of the folder that you have your PowerGallery installed in? When you are in the admin area what does the include code look like for the gallery?