QtQuickDesigner for symbian component on windows and Mac is different from Linux

Steps:
1. Create a QtQuick Application for symbian component using the wizard
2. Activate the MainPage.qml and switch to designer mode

Expected result:
Design canvas can be seen

Actual result:
The Design canvas can't be seen and the default coordinate of the page is (73.0,-66.0)

Comment:
SDKTestRound17

On Linux, the canvas is white color and user can differentiate it from the border; but on Windows and Mac, the canvas is black, and if you add some component to it, the y coordinate of the component is always negitive.

The phenomenon is same if selecting Meego/Harmattan component, the canvas is still black.