TableView flicking misbehaves with Window ancestor

If the top-level Item is a Window, then TableView flicking mis-behaves as described below.

SCENARIO #1: One column is narrower than the others.

Flicking left initially leaves the table stopped partially out of view, i.e. so the right edge of the grid is in the middle of the viewport, even though the grid is larger than the viewport.   

However the problem disappears after flicking vertically back and forth a few times (to cause delegates to be recycled?)    Then behavior becomes normal, with the entire viewport filled with a portion of the grid at all times.

This seems to happen when top-level Item is a Window rather than just a Rectangle.

STEPS TO REPRODUCE:

1.  Run attached demo2.qml with qmlscene
2. Move the table left as far as possible (I am using a mouse on a desktop computer)

  RESULT: A large portion of the background Window becomes visible on the right
  EXPECTED: Flicking should stop before obscuring more data than necessary

3. Flick up and down a few times

  RESULT: The above behavior stops, and horizontal flicking works as expected.\

SCENARIO #2: One row shorter than other rows:

This makes vertical flicking completely frozen – it is impossible to flick off-screen rows into view.  Please run the attached demo_frozenvertical2.qml

This problem seems sensitive to the exact size of the Window; making the viewport smaller, either by changing the initial height: of the Window, or by resizing it with the mouse while running, makes the problem disappear.