Drag and drop in treeview.

I have a problem getting a treeview to behave like i want it to.

I'll try to explain the problem;
I scroll down the treeview enough so that the top most leaf isn't visible. If I then drag one of the leafs and move it to the top of the control it won't scroll up.

You can find the same (working) behavior in windows explorer.

Is this a limitation to the treeview or have i done something wrong?