Comment 11 for bug 1095780

Maybe these commits, not included in Qt 4.6.2 causing our problem:
http://www.qt.gitorious.org/qt/qt/commit/951cceac68b4a6cf38da83b69dcde2c8109342a2
http://www.qt.gitorious.org/qt/qt/commit/acc1a2bd5520369c690c2769f067aec6bfd869f2

I wander if get any better if we use:
painter->end();
m_pButton->render(painter);
without the detour of render to a QImage, convert to QPixmap and draw.