Drag and Drop icon does not update itself appropriately when the cursor enters to an invalid drop area.

This can be demoed with modified DraggableIcons example.
Modify main.cpp by setting layout margin to 200 (to get extra space around widget) and run the app.

Drag icon(s) off from the dragwidget area, there's no indication that drop is not valid.
If Icon is dragged outside the whole window, then indication is shown.

This works fine on Linux and Mac with Qt 4.7.4. On Windows I reproduced this bug with Qt 4.6.2, 4.7.2, 4.7.4 and 4.8.0 RC1 versions.