ImageTk的问题（来自Anaconda发行版）

Question

我最近（昨天......）切换到了Anaconda，现在我遇到了ImageTk.PhotoImage的问题：

>>> im = Image.open(fn) # fn is a png image
>>> im
<PIL.PngImagePlugin.PngImageFile image mode=RGBA size=411x484 at
0x10F9D4750>
>>> imtk = ImageTk.PhotoImage(im)
Exception AttributeError: "'PhotoImage' object has no attribute
'_PhotoImage__photo'" in <bound method PhotoImage.__del__ of
<PIL.ImageTk.PhotoImage object at 0x10f9d45d0>> ignored
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/Users/eduardomartinez/anaconda2/lib/python2.7/site-packages/PIL/ImageTk.py", line 112, in __init__
  self.__photo = tkinter.PhotoImage(**kw)
  File "/Users/eduardomartinez/anaconda2/lib/python2.7/lib-tk/Tkinter.py", line 3367, in __init__
  Image.__init__(self, 'photo', name, cnf, master, **kw)
  File "/Users/eduardomartinez/anaconda2/lib/python2.7/lib-tk/Tkinter.py", line 3304, in __init__
    raise RuntimeError, 'Too early to create image'
RuntimeError: Too early to create image

这曾经工作过。任何线索？