[copied from my reply in your duplicate private support ticket]
I see what you mean... it results in "Timed out waiting for command to be handled". I've filed a bug on this here. We'll see what our software developers can do about it.
What is it you're trying to accomplish? Could you use the standard DragDrop method? e.g.
Or else break it up into these three calls?
All the best,
the Telerik team