[PyQt] simple newb question

[Neal Becker]

import sys
from PyQt4.QtCore import *
from PyQt4.QtGui import *

app = QApplication (sys.argv)
ret = QMessageBox.question (None, "My App", "You have mail")
print ret

Why doesn't this display any icon?  The docs say that I should see an icon, varying with whether I used '.question', or '.warning', etc.