Finally you come to my rescue

Your code is invalid.
Why does it work with Qt Quick 1.0?

You cannot modify the model from within a worker thread. If you really have to use a thread, then emit a signal from it and connect it to a slot in the model that will perform the addition from the main thread.
Yes i guessed that because as stated, when i used the QThread way (similar to what you suggest), everything worked fine. Why can't model be updated in a worker thread? It's not a UI component. Could you please also give me a link to the documentation where this is stated? It's not in QAbstractItemModel doc.