Check out this thread, post #4 showthread.php?t=10555&highlight=jquery
You are using jQuery, so that is causing a conflict. If you edit the gallery.js file for your gallery - and change $( to document.id( - that should fix the issue.
However, I also noticed 404 errors when it was trying to load some of the powergallery javascript files. Can you double check the /js main folder and /js folder for your gallery are uploaded to the server?