# running on Windows XP, Python 3.1

from tkinter import *
from tkinter import ttk

# repair
def fix_Tcl_string_error(s):
    
    if '\\' in s and not ' ' in s:
        return '{'+s+'}'

    else:
        return s

# the root
root = Tk()
root.geometry('+300+300')

# a frame
f1 = ttk.Frame(root)
f1.pack()

# a combobox
cb = ttk.Combobox(f1,width=72)
cb.pack()

# the problem
test_strings = [r'C:\Python31\Lib\tkinter\test\test_ttk', # path, no spaces
                r'C:\Documents and Settings\Administrator\desktop', # path with spaces
                'oneword',
                'two words',
                'this /3 that',
                'special* character?',
                r'escaped\? special\\ characters\*'
                ]

# make repairs
##test_strings = [fix_Tcl_string_error(s) for s in test_strings]

# add to combo box
cb['values'] = test_strings
cb.current(0)

# run
root.mainloop()