In py3k branch r57057, when I run::

  import Tkinter

  tk = Tkinter.Tk()
  text = Tkinter.Text(tk)

  def callback(event=None):
      return

  text.bind('<Control-space>', callback)
  text.pack()
  text.focus_set()
  tk.mainloop()


when I press C-space I get this exception::

  Traceback (most recent call last):
    File "spacefailure.py", line 13, in <module>
      tk.mainloop()
    File "/usr/local/lib/python3.0/lib-tk/Tkinter.py",  line 1022, in mainloop
      self.tk.mainloop(n)
  UnicodeDecodeError: 'utf8' codec can't decode bytes in position 0-1: illegal encoding

The strange thing about it is that other bindings work
as expected.

I'm running on ubuntu feisty.