FileDialog does not start up in the declared folder

FileDialog { folder: "/var/tmp" } 

does not start up in the given directory, whereas if you assign the folder later (as qtdeclarative/examples/quick/dialogs/systemdialogs/FileDialog.qml does when you click the "go to /tmp" button), it will work. This happens when the dialog is realized as a QFileDialog, but the pure-QML implementation is OK.