QFileDialog extremely slow on Windows (XP)

QFileDialog is extremely slow on any QT (@Windows XP). I can see that it is a bit faster in release-builds than debug - but still very very slow.
Try the code. Don't forget to visit
c:\windows\system32
(or where this folder is on your system). Notice that other folders can contain many more files.

Under Linux I can browse (the same folders) a lot faster on the same files (through share (samba)). It is acceptable fast - but I did see a 'render bug' once.
(By render bug I mean that you paint while the files are updated - I would suggest that if you can't fetch in the right order then wait with the painting. Don't paint/update. In Windows I can move my mouse to an object and (almost) click at it and then 10-20 new icons appear - and the one I wanted to click on has moved.)

The Windows version of QFileDialog seems to be something like a factor 15 (1500%) slower than the Linux-version.

I know I can use the static functions (and get the native Windows dialogs and I probably will) but I see no reason for QFileDialog to be that slow on Windows. With QT I could program a far faster filedialog myself.

(Just showing the dialog is also somewhat slow ...)

void browseLogFolder()
{
  QFileDialog fd;
  if (fd.exec()==QDialog::Accepted)
  {
    QStringList res = fd.selectedFiles ();
    if (res.count()==0)
      return;
    qDebug() << res[0];
  }
}

void thisIsFastButNotAsPowerFull()
{
  QString res = QFileDialog::getOpenFileName(0,"select something");
  qDebug() << res;    
}

int main(int argc, char *argv[]) 
{  
  QApplication app(argc, argv); 
  browseLogFolder();
  return 1; 
}