When I do in Python 2.x (e.g. 2.6) next:
----------------------------
import Tkinter as T
import tkFileDialog as F
t = T.Tk()
dn = F.askdirectory()
----------------------------

It pop-ups the dialog, it is OK. Analogical case for Python 3.0 does not
work, at least on my Linux box:
----------------------------
import tkinter as T
import tkinter.filedialog as F
t = T.Tk()
dn = F.askdirectory()
----------------------------

It just writes an error message below:
----------------------------
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python3.0/tkinter/filedialog.py", line 430, in
askdirectory
    return Directory(**options).show()
  File "/usr/local/lib/python3.0/tkinter/dialog.py", line 20, in __init__
    cnf['title'], cnf['text'],
KeyError: 'title'
----------------------------

When I had tried to put there all the parameters it was asking for, it
just put some nonsense window.