Hi.
although clearly stated here (http://www.telerik.com/help/aspnet-ajax/asyncupload-drag-and-drop-upload.html) that dropzone property is available starting Q3 2011, while using Q2 2012 version I do not see the dropzones attribute available in the RadAsyncUpload.
Obviously I tried to ignore it and simply add that attribute, but that did not work either.
my control looks like