--- a/frontends/src/wix/xmlui.py	Sun Dec 09 23:24:53 2012 +0100
+++ b/frontends/src/wix/xmlui.py	Sun Dec 09 23:25:51 2012 +0100
@@ -31,13 +31,13 @@
 class XMLUI(wx.Frame):
     """Create an user interface from a SàT xml"""
 
-    def __init__(self, host, xml_data='', title="Form", options=[], misc={}):
+    def __init__(self, host, xml_data='', title="Form", options = None, misc = None):
         style = wx.DEFAULT_FRAME_STYLE & ~wx.CLOSE_BOX if 'NO_CANCEL' in options else wx.DEFAULT_FRAME_STYLE #FIXME: gof: Q&D tmp hack
         super(XMLUI, self).__init__(None, title=title, style=style)
 
         self.host = host
-        self.options = options
-        self.misc = misc
+        self.options = options or []
+        self.misc = misc or {}
         self.ctrl_list = {}  # usefull to access ctrl
 
         self.sizer = wx.BoxSizer(wx.VERTICAL)