QThread confusion, yet another question about quiting thread

[Talei]

SOLVED
Change:

connect( th, SIGNAL( started() ), vFilePrev, SLOT( makePreview() ));

connect( th, SIGNAL( started() ), vFilePrev, SLOT( makePreview() ));

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and:

public slots:
     void makePreview(  );

public slots:
     void makePreview(  );

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I would like to know why when I use
connect( th, SIGNAL(started()), this, SLOT(threadStarted()));
the function in this SLOT is run but thread don't seams to react properly (is it because the SLOT is in the same Thread as the QThread, with is GUI thread?).
I saw in the sysinternals that thread is actually created but never quit's, but when I connect actual Thread code to the SIGNA(started()); QThread react properly (at least with this simple example).