Unable to see wx.ICON_QUESTION in wx.MessageBox

I am using wxPython 3.0.1.1 on a Windows Vista 32-bit platform. If I try the following:

def ShowMessage(self):
         wx.MessageBox('Download completed', 'Info',
             wx.OK | wx.ICON_INFORMATION)

This works as expected. However, when I try:

def ShowMessage(self):
         wx.MessageBox('Download completed', 'Info',
             wx.OK | wx.ICON_QUESTION)

No icon appears and no error or warning message is given! and this also true for:

def ShowMessage(self):
         wx.MessageBox('Download completed', 'Info',
             wx.YES_NO | wx.ICON_QUESTION)

Why?

I found the same thing on Windows 7 with 3.0.1-classic-msw

···

On Wednesday, October 29, 2014 7:58:19 AM UTC-7, Birdy wrote:

I am using wxPython 3.0.1.1 on a Windows Vista 32-bit platform. If I try the
following:

def ShowMessage(self):

     wx.MessageBox('Download completed', 'Info',

         wx.OK | wx.ICON_INFORMATION)

This works as expected. However, when I try:

def ShowMessage(self):

     wx.MessageBox('Download completed', 'Info',

         wx.OK | wx.ICON_QUESTION)

No icon appears and no error or warning message is given! and this also true for:

def ShowMessage(self):

     wx.MessageBox('Download completed', 'Info',

         wx.YES_NO | wx.ICON_QUESTION)

Why?