QGraphicsTextItem is blurring at certain regions

[wagmare]

hi friends,
i am encountering this problem second time ..

on the QGraphicsRectItem

QFont font;
        textItem = new QGraphicsTextItem(this);
        if(currentType == X86_TYPE){
                font.setPixelSize(16);
                textItem->setPos(15,12);
        }else{
                font.setPixelSize(13);
                textItem->setPos(6,4);
        }
        textItem->setFont(font);
        textItem->setDefaultTextColor(QColor(111, 120, 122));
        textItem->setPlainText(QString("Pin %1").arg(currentIndex));

QFont font;
        textItem = new QGraphicsTextItem(this);
        if(currentType == X86_TYPE){
                font.setPixelSize(16);
                textItem->setPos(15,12);
        }else{
                font.setPixelSize(13);
                textItem->setPos(6,4);
        }
        textItem->setFont(font);
        textItem->setDefaultTextColor(QColor(111, 120, 122));
        textItem->setPlainText(QString("Pin %1").arg(currentIndex));

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i am positioning the QGraphicsTextItem on it ..

some times the text is blurred in certain region ... previous time its at the top region of QGraphicsView() and now in bottom
see my screenshot i attach with this thread
please help me to solve this problem ..

P.S.
my QGraphicsView is a embedded widget of another QGraphicsView()