Jim, thank you so much! I downloaded your version and it worked after I made the "$('some_element').centerInViewport();" change to assets.js (I assume you will do this eventually to your source).
Presumably, your changes will be merged into the "official" version at some point. For those of us, like me, who are not git masters, what commands can we use to keep our extensions up-to-date with the latest changes made on github? "git merge" perhaps? Thanks again. -- marshal