Windows: QPainter errors when maximizing/resizing window

QPainter::begin: Paint device returned engine == 0, type: 3
QPainter::setCompositionMode: Painter not active
QPainter::fillRect: Painter not active
QPainter::setCompositionMode: Painter not active
QPainter::setBrush: Painter not active
QPainter::setPen: Painter not active
QPainter::drawRects: Painter not active
QPainter::setPen: Painter not active
QPainter::setFont: Painter not active
QPainter::setFont: Painter not active
QPainter::setBrush: Painter not active
QPainter::setPen: Painter not active
QPainter::setPen: Painter not active
QPainter::setBrush: Painter not active
QPainter::setPen: Painter not active
QPainter::setPen: Painter not active
QPainter::setBrush: Painter not active
QPainter::setPen: Painter not active
QPainter::setPen: Painter not active
QPainter::end: Painter not active, aborted