Buttons with line breaks don't display properly on Mac OS X

This code works fine in Windows. On Mac OS X it only shows "Multiple" in the button and everything past the newline gets wiped out. I'm running Python 2.6.5 on Mac.

import Tkinter as tk
class App:
    def __init__(self, master):
        self.a_button = tk.Button(master, text="Multi开发者_StackOverflow中文版ple\nLines\nOf Text")
        self.a_button.pack()

ROOT = tk.Tk()
APP = App(ROOT)
ROOT.mainloop()

Mac native pushbuttons don't let you do that; they have 3 predefined heights for the various control sizes and that's it. Other button styles do support arbitrary dimensions; one option is to use a Tile button instead:

    self.a_button = tk.Widget(master, 'ttk::button',
                              dict(text="Multiple\nLines\nOf Text"))