Can you try it? it is about me or it is a bug?
In [1]: import Image
In [2]: im = Image.open("r.png")
In [3]: type(im)
Out[3]: <type 'instance'>
In [4]: thm = im.thumbnail((200,200))
In [5]: type(thm)
Out[5]: <type 'NoneType'>
--
Mirat Can Bayrak <miratcanbayrak at gmail.com>