diff --git a/IPython/gui/wx/wxIPython.py b/IPython/gui/wx/wxIPython.py
index aac8915..d6fd63d 100755
--- a/IPython/gui/wx/wxIPython.py
+++ b/IPython/gui/wx/wxIPython.py
@@ -87,6 +87,7 @@ class MyFrame(wx.Frame):
         warn_text = 'Hello from IPython and wxPython.\n'
         warn_text +='Please Note that this work is still EXPERIMENTAL\n'
         warn_text +='It does NOT emulate currently all the IPython functions.\n'
+        warn_text +="\nIf you use MATPLOTLIB with show() you'll need to deactivate the THREADING option.\n"
         
         dlg = wx.MessageDialog(self,
                                warn_text,