Flickable.topMargin doesnt work correctly on Item with default property

run the attached example, there should be 20 red pixels appearing initially on the top (ListView.topMargin == 20), but it doesnt.

the topMargin set on ListView on the attached example doesnt appear initially if there are more items in the model than fit on the screen.

in the attached example, if you comment out the Page element, then the topMargin works correctly.