title: lift() method of python's Tkinter package not working
body: <p>I am trying to build an application with a main window, and a background thread that checks a certain condition in a loop, and when the condition is met, brings the main window to the front.
  To bring the window to the front i use the <code>lift()</code> method, but it doesn't work.
  So I did the following experiment from the python command line:</p>
  
  <pre><code>from Tkinter import *
  root = Tk()
  </code></pre>
  
  <p>A tk window appears. Minimize the window and then:</p>
  
  <pre><code>root.lift()
  </code></pre>
  
  <p>Nothing happens. I also tried start the window's mainloop before lifting:</p>
  
  <pre><code>import thread
  # start mainloop in separate thread so we can continue typing
  thread.start_new_thread(root.mainloop, ())
  root.lift()
  </code></pre>
  
  <p>Again, nothing happens. In my actual code it is even worse - once I call <code>lift()</code>, the window is stuck and stops responding.</p>
  
  <p>What am I doing wrong?</p>
  
  <p>(I'm using Python 2.7.2 on Windows 7.)</p>