QFileSystemModel seems to make the application hangs

When QFileSystemModel has set root path to a Windows network share, application hangs as soon Ethernet cable is unpluged.
When the cable is pluged back the application will respond again after 4 to 5 seconds.

Application runs on Linux (It is a customized version of the Angstrom distribution). The application uses the cifs-utils package to connect to a shared folder on Windows 7.

Problem happens when network cable is plugged out before setRootPath:

int main(int argc, char *argv[])
{
QApplication a(argc, argv);

QFileSystemModel *model = new QFileSystemModel;
model->setRootPath("Path to shared network drive");
QTreeView *tree = new QTreeView();
tree->setModel(model);
tree->show();

return a.exec();
}