title: wxPython controls not clickable
body: <pre><code>//if I use BoxSizer instead of StaticBoxSizer, the button is clickable.
  //if there is a radio button under StaticBoxSizer, it is clickable,
  //but the button is not
  row1 = wx.StaticBoxSizer(wx.StaticBox(panel, -1, 'this is row one'), orient=wx.HORIZONTAL)
  row1.Add(label1,0,wx.TOP | wx.RIGHT,7)
  row1.Add(self.fileCtrl)
  row2 = wx.BoxSizer(wx.HORIZONTAL)
  
  //for everything in row2, neither buttons nor radio buttons are clickable
  actionBox = wx.StaticBoxSizer(wx.StaticBox(panel, -1, 'asdfasdf'), orient=wx.VERTICAL)
  
  actionRow1 = wx.BoxSizer(wx.HORIZONTAL)
  actionRow1.Add(wx.StaticText(panel, -1, 'blah blah ', (5, 5)))
  actionRow1.Add(self.mailRadio)
  actionRow2 = wx.BoxSizer(wx.HORIZONTAL)
  actionRow2.Add(wx.StaticText(panel, -1, 'lah dee dah', (5, 5)))
  actionRow2.Add(self.uploadRadio,5)
  actionBox.Add(actionRow1,0,wx.EXPAND)
  actionBox.Add(actionRow2)
  row2.Add(actionBox)
  
  wrapper = wx.FlexGridSizer(2,1,5,5)
  wrapper.AddGrowableCol(0)
  wrapper.Add(row1,0,wx.TOP | wx.LEFT | wx.RIGHT | wx.ALIGN_CENTER,15)
  wrapper.Add(row2,0,wx.ALL | wx.ALIGN_CENTER,15)
  panel.SetSizerAndFit(wrapper)
  self.Centre()
  self.Fit()
  </code></pre>
  
  <p>I'm testing this in OS X, but I need it to work on windows too. Pretty new to this so this is confusing me. Is there something like css z-index that I have to set?</p>