QDockWidget: vertical splitter that separates docks that have been undocked then re-docked vertically responds disproportionately to small mouse movements

To reproduce the problem, build the attached example with Qt 4.6.

Issue 1:

If you start Main Window Debug.exe, either form the release or form debug folder, and move the vertical separator left or right, just that it is not in the middle and slightly resize the window, that will reset the vertical separator to the middle of the main window. I could not reproduce this but it could depend on whether the frames inside the layout are in layouts or not.

Issue 2:

Run it and undock the widgets so they are floating. Then re-dock them so they are aligned vertically and out of their original order. Now try dragging the vertical splitter. You should find that it moves wildly in response to very small horizontal mouse movements.

If you build against Qt 4.5.2 this isn't the case.