Thank you for writing back.
class uses its own drag drop mechanism, different than the default OLE drag & drop mechanism. That is why default drag & drop events do not get fired. In this scenario you can use BeginDrag
methods of RadItemDragDropManager.
If this does not help, describe in detail the desired functionality and behavior that you want to achieve and we will be glad to help further.
I am looking forward to your reply.
the Telerik team