GraphicsItem is movable my mouse outside of its shape.

The determination if an item is under the mouse cursor is not working correctly. In the attached minimal project, the mousecursor changes OUTSIDE of the circle, if the mouse approaches the circle from top-right. The item is then movable.
This is reproducible with Qt libs 4.7.1 from the website, with self-compiled static 4.7.1 and 4.7.1 compiled with Microsoft VC 2010.
Qt 4.6.3 on the other hand works as expected.