Different point size for the font created using QFont class and returned by QFontDialog

setFont() test case from tests/auto/qfontdialog test case is failed.
00:48:03.337 [QTestLib] FAIL! : tst_QFontDialog::setFont() Compared values are not the same Actual (QFontInfo(f2).pointSize()): 6 Expected (QFontInfo(f1).pointSize()): -1 Loc: [K:\sf\mw\qt\tests\auto\qfontdialog\tst_qfontdialog.cpp(162)]

    QString fontName = "Arial";
    int fontSize = 24;

    QFont f1(fontName, fontSize);
    f1.setPixelSize(QFontInfo(f1).pixelSize());
    QTimer::singleShot(2000, this, SLOT(postKeyReturn()));
    QFont f2 = QFontDialog::getFont(&ok, f1);
    QCOMPARE(QFontInfo(f2).pointSize(), QFontInfo(f1).pointSize());

Point size is different for the same font but created in different manner: one by QFont object and second by QFontDialog.
The QFont object returned by QFontDialog also should return -1 for the font with specified pixel size but returned 6.
It is reproduced only on Symbian devices. It is not reproduced on Windows and emulator.