Thanks so much for your reply! I have not uploaded the updates to the live site, so it’s not available for you to browse, but I’m sure your tip about jQuery migrate is the the answer.
If you are using the latest version of WordPress, the qTip plugin will not work. It uses a browser sniffer function that is deprecated in jQuery 1.10.2.
Ross – is there any plan to update the tooltip functionality in this plugin? I really like the way it works, and having the ability to style the calendar in the sidebar or on a full page; but the qTip incompatibility means I can’t update to WP 3.8…