Ok, I'm having a slight bit of confusion writing my own jQuery UI widget plugins. The problem lies in the destroy function. In the docs, it says to put the default destroy first then write other things particular to the widget after it. $.Widget.prototype.destroy.apply(this, arguments); // default destroy // now do other stuff particular to this widget See http://jqueryui.com/docs/Developer_Guide However in their example scripts (those being the actual pluings for jQuery Ui released code, does it the opposite. The $.Widget.prototype.destroy.apply(this, arguments); is at the end of the function. See http://dev.jqueryui.com/browser/trunk/ui/jquery.ui.progressbar.js (and all of the other built in widgets as well) So which is it? The way the current widgets are written, or by the explanation in the code comment in the Developer_Guide?