We upgraded our application from Q2 to Q3 build 2015.3.930 this week. Our select event handlers for ComboBoxes are no longer respecting e.preventDefault(). We use this technique to display a confirmation dialog in certain cases.
I recreated the issue in the dojo to confirm the issue exists in the Q3 ​release and not the Q2 release: http://dojo.telerik.com/olIsi
fabric.bind("select", function(e){ e.preventDefault(); });