wxPython broken notebook on Linux/Gtk3

badtab.py

import wx

class Tab1(wx.Panel):

	def __init__(self, parent):
		wx.Panel.__init__(self, parent)
		self.l = wx.StaticText(self, label="Text")
		self.sizer = wx.GridBagSizer(0,0)
		self.sizer.Add(self.l, pos=(0,0))
		self.SetSizer(self.sizer)

class Tab2(wx.Panel):

	def __init__(self, parent):
		wx.Panel.__init__(self, parent)
		self.mode = wx.RadioBox(self, label="Mode", choices=["1","2","3"])
		self.sizer = wx.GridBagSizer(0,0)
		self.sizer.Add(self.mode, pos=(0,0), span=(1,6), flag=wx.ALL|wx.ALIGN_CENTER, border=20)
		self.SetSizer(self.sizer)

class BadTab(wx.Frame):
	def __init__(self):
		wx.Frame.__init__(self, None, title="BadTab", size=(300,200), style=wx.DEFAULT_FRAME_STYLE & ~(wx.RESIZE_BORDER | wx.MAXIMIZE_BOX))
		self.panel = wx.Panel(self)
		self.notebook = wx.Notebook(self.panel)
		self.tab1 = Tab1(self.notebook)
		self.tab2 = Tab2(self.notebook)
		self.notebook.AddPage(self.tab1, "Tab 1")
		self.notebook.AddPage(self.tab2, "Tab 2")
		mainbox = wx.BoxSizer(wx.VERTICAL)
		mainbox.Add(self.notebook, 1, wx.EXPAND | wx.ALL, 10)
		self.notebook.Layout()
		self.panel.SetSizer(mainbox)
		self.panel.Layout()
		self.Centre()
		self.Show()

app = wx.App()
gui = BadTab()
app.MainLoop()