matplotlib/pylab problems with wxpython 2.9.2.1 -

Hi all,
I'd like to ask about some issues I am having with using matplotlib
with the latest wxpython version 2.9.1.1;
I already mentioned that on the wxpython list:
https://groups.google.com/forum/#!topic/wxpython-users/vG-5NJ4vXnc
but it is unclear whether this is a bug in wx or a possible problem
with the backend_wx which happened to be "tolerated" in wxpython
sofar.

Simple code using the WX backend seems to
work ok in 2.8.12.1 and 2.9.1.1 but not in 2.9.2.1.
The graph canvas is inactive and transparent - showing the
screen below this active frame; with resizing and moving this frame,
there are artefacts and display glitches and redrawing errors around
it, but the graph is not shown and there are no exceptions thrown.

(I am using Python 2.7.2, matplotlib 1.0.1; win 7 and Win XP; wxPython
32bit (unicode))

# # # # # # # # # # # pylab - wxPython # # # # # # # # # # # # # # # # #

#! Python
# -*- coding: utf-8 -*-

import wxversion
# wxversion.select('2.8') # 2.8.12.1 ok
# wxversion.select('2.9.1') # 2.9.1.1 ok
wxversion.select('2.9.2') # 2.9.2.1 !! display errors in pylab

import wx

import matplotlib # http://matplotlib.sourceforge.net/

# matplotlib.use('WXAgg') # ok in both, wx 2.8 and 2.9.x
matplotlib.use('WX')

import pylab

pylab.plot(range(3), range(3), label="a")
pylab.show()

# # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # #
A very simple version without pylab shows the same problem:
# # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # #

#! Python
# -*- coding: utf-8 -*-

import wxversion
# wxversion.select('2.8')
wxversion.select('2.9.2')
import wx
import matplotlib
matplotlib.use('WX')
from matplotlib.backends.backend_wx import FigureCanvasWx as
FigureCanvas # err on wx 2.9.2
# from matplotlib.backends.backend_wxagg import FigureCanvasWxAgg as
FigureCanvas # ok
from matplotlib.figure import Figure

class CanvasFrame(wx.Frame):
    def __init__(self, ):
        wx.Frame.__init__(self, None, -1, 'CanvasFrame', size=(550,350))
        self.figure = Figure()
        self.axes = self.figure.add_subplot(111)
        self.axes.plot(range(4),range(4))
        self.figure_canvas = FigureCanvas(self, -1, self.figure)
        self.sizer = wx.BoxSizer(wx.VERTICAL)
        self.sizer.Add(self.figure_canvas, 1, wx.LEFT | wx.TOP | wx.GROW)
        self.SetSizer(self.sizer)

if __name__=='__main__':
    app = wx.App(False)
    frm = CanvasFrame()
    frm.Show(True)
    app.MainLoop()

# # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # #

It is likely to depending on
matplotlib.backends.backend_wx :: FigureCanvasWx (or some inherited
classes), but I had sofar no success in finding the problematic code.

Could you maybe give any pointer where to look into, or maybe how to
activate some exception tracebacks etc? (Changing _DEBUG = 5 in
...\matplotlib\backends\backend_wx.py to other values doesn't seem to
have this effect).

Thanks in advance,
    vbr