Since it changes geometry of the items after maybe it's another quirk. Try calling QStyle::unpolish and then QStyle::polish() with the toolbar.

QTextEdit::toHtml() gibt schon gültiges HTML zurück - nicht nötig da noch einmal was zu konvertieren (was eh nicht mehr vorhanden ist). ß wird übrigens falsch konvertiert...

Can you check with a more recent version of Qt ? I can't reproduce your problem, I don't know what i should be. But if I remove the showPopup method it shows the combobox at the right place for OS X.

@SGaist Thank you for your answer, I'm gonna try in this way. If it works, i'll post it here because I'm sure it could be helpfull for someones... I'm actually surprise to see that it's not implemented within the QListWidget class!