Dates not properly localized

With Qt-4.8.0 I'm not getting month names translated. The following two runs show the output from the program listed further below compiled against qt-4.7.3 and qt-4.8.0. The correct result is "marts" as coming from the qt-4.7.3 version. It doesn't work correctly with other languages, such as se_SV and de_DE.

[ts@magnesium playdate]$ LANG=da_DK.utf8 rhel6-qt47/playdate
Month 3: "marts"
[ts@magnesium playdate]$ LANG=da_DK.utf8 rhel6-qt48/playdate
Month 3: "March"

#include <QCoreApplication>
#include <QLocale>
#include <QtDebug>

int main(int argc, char *argv[]) {
QCoreApplication app(argc, argv);
qDebug() << "Month 3: " << QLocale().monthName(3);
return 0;
}