When setting a palette on a QComboBox's lineedit then it gets disregarded on Windows Vista

#include <QtGui>

int main(int argc, char **argv)
{
    QApplication a(argc, argv);
    QWidget w;
    QComboBox *cb = new QComboBox(&w);
    cb->addItems(QStringList() << "A" << "B" << "C");
    cb->setEditable(true);
    QPalette p = cb->lineEdit()->palette();
    p.setColor(QPalette::Base, Qt::red);
    cb->lineEdit()->setPalette(p);
    w.show();
    return a.exec();
}