QPushbutton Flat property and icon appearance.

Hi,
Previously i am working on QT4.1 and setting push button's icon and setting Flat property to true.
But when same project is compiling and running with the QT4.2.0 then icons are moving with mouse click or when the form load some icons are already moved and not appearing properly.
but when i set Flat property to false then the icons are not moving with mouse click and properly appearing.

My requirement is show push Button clickable so i am setting Flat property of button to true.

How can i set the Flat property of button to true and icon is not moved when form load and not moved by mouse click.

Thanks and Regards