... This contrib packages the third-party Behaviour Javascript event library, available from http://bennolan.com/behaviour/ . Changed: . ... Behaviour code leaks memory on Windows Explorer prior to version 7. To prevent leaking, set the element variable to null : var myrules = { 'table.test td' : function(element) { element.onmouseover = function() { this.style.backgroundColor = highlightColor; return false; } element = null; // by setting this IE will not leak } }; Behaviour.register(myrules); . ...