I tried to simulate dragging and dropping of elements in a tree, but it seems it doesn't work.

Here is the page where I tried to use drag and drop:
http://dev.sencha.com/deploy/ext-4.0...e/reorder.html (it's a ExtJS example)

I expanded the tree-folders "app" and "button" and tried to drag and drop "Button.js" from "button"-folder to "app"-folder.

I tried the following code (after expanding the two folders) in the Selenium IDE:
mouseDownAt: "//tr[8]/td/div" (that's "Button.JS")
mouseMoveAt: "//tr[3]/td/div" (that's "app")
mouseUpAt: "//tr[8]/td/div"

and also I tried:
dragAndDropToObject: "//tr[8]/td/div", "//tr[3]/td/div"

both didn't work. Any suggestions?