Thank you so much! It worked, although I've also had to change "qApp" to "this" in the connect sentence (connect(ui->Exit, SIGNAL(triggered()), qApp, SLOT(ExitClick()));). What I don't understand is why I have to use ui-> to refer to "Exit" QAction, but not to refer to "statusBar" status bar. By the way, do you know why the hints (the "WhatsThis" messages) in the status bar don't appear?

Thanks again.