Using Python 3.3 on W7x64 I wanted to create a file dialog that allows me to select multiple files.
The code below is an example of how to re-create the bug.

# -*- coding: iso-8859-15 -*-
# Python 3

import tkinter 
import tkinter.filedialog  

def callback():
    name = tkinter.filedialog.askopenfilenames() 
    print(name)
     
tkinter.Button(text='File Open', command=callback).pack()
tkinter.mainloop()


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THE PROBLEM:
When selecting any file in the windows library\* folders (those: http://beingpc.com/wp-content/uploads/2011/05/How-to-Change-the-Windows-7-Library-Icon.jpg ) the return value that will be printed is always {}.
tkinter.filedialog.askopenfilename() (without the 's') works fine also in those directories.

Can anyone reproduce this behavior?

There was a issue about people not being able to open windows 'library' files from Idle, but it was determined not to be an Idle problem. I cannot find it now. The outcome may have been that this was presumed to be a tk bug, but your report about the alternate dialog is interesting. it.

I guess tkinter.wantobjects is 0 for you?

This patch should fix the issue (as many other issues).

See also #3015 and #5712.

Already applied in issue3015.

I'd like this issue to be reopened.  It does not appear resolved.  It is different from the wantobjects=False issue.

Windows 7 has 'libraries' which are folders containing the contents of more than one folder.  For instance, on my computer
   > Libraries > Documents
presents the contents of the following 2 folders simultaneously:
   C:\Users\aneufeld\Documents
   C:\Users\Public\Documents

If you execute the script listed in the original bug report, press the [File Open] button, press "Libraries" from the left bar, double click "Documents" in the main area, and select one or more *FILES* in the displayed list of files, I get back:
   ('',)

On the other hand, if I press "Computer" on the left bar, and navigate through "C:", "Users", "aneufeld", "My Documents", and select the SAME FILES, I get back:
   ('C:/Users/aneufeld/Documents/timelog.txt', 'C:/Users/aneufeld/Documents/notes.txt')

From the "> Libraries > Documents" folder, if you navigate into any real folder, the problem goes away.  For example, with the folder ATS in My Documents, press the [File Open] button, press "Libraries" from the left bar, double click "Documents" in the main area, double click ATS, and select the two files, I get:
   ('C:/Users/aneufeld/Documents/ATS/readme.txt', 'C:/Users/aneufeld/Documents/ATS/Changes.txt')

The issue is, when the file "Foo.txt" is selected in a Library folder, such as "Documents", the dialog does not know if that file should be:
   C:/Users/aneufeld/Documents/Foo.txt
or
   C:/Users/Public/Documents/Foo.txt
and returns a null string for the filename.