See the attached QML file for reproducing the problem.
See the attached 3 snapshots for illustration of the problem.

Steps to reproduce:

1. Start dragging one of the white rectangles (snapshot1.png).
2. Keep on dragging (can take 10 seconds or more) until the rectangle suddenly disappears (snapshot2.png).
3. Try to start dragging another rectangle. It disappears on mouse press (snapshot3.png).

Notice that the "Children count" text visualizes the children count. It drops to 1 and then 0.

I have found two ways to make the problem disappear:

1. Comment out the onPositionChanged signal handler.
OR
2. In myComponent.createObject(null), replace null with itemContainer.

This strange behavior causes serious problems in my application(s).

Might be related to: QTBUG-15085?